2208: Latest news on the US relay appeal. The appeal is "being heard and is active" according to our sources at USA Track and Field. One more thing. Berlino the Bear was racing with Usain today. What a perfect birthday for the Jamaican. Berlino runs the 100m. Night. See you tomorrow.
2205: That's it folks. A scrappy old night with the rain and the confusion over the US disqualification. But stunning athletics drama as well. A mixed night for the Brits. Thanks for all your comments. Another top effort. Men's marathon in the morning. Greg Rutherford and Chris Tomlinson in the long jump final, Steve Lewis goes in the pole vault final, other finals are hammer, women's 5,000m, the 4x400m men and women relay heats get going with Saturday finishing up with the men's 4x100m final. Will the Americans be there? We shall wait and see.
2159: Nervy times for the women's discus. Big smiles for 21-year-old Samuels as she watches Grasu chuck her discus into the cage netting. Not great. Samuels is all smiles and she looks very very VERY HAPPY! Gold for the Aussie - their first of the championships. DANI SAMUELS IS DISCUS CHAMPION. Barrios gets silver and Grasu with bronze.
2147: Things hotting up for the women's discus final. Nicoleta Grasu in the lead so far with 65.20. HOLD ON. Aussie Dani Samuels twists her body that's wearing a hideous bright green suit and hurls a 65.44. She screams the roof off. She's in the lead. Incredible effort. Yarelis Barrios in bronze position.
Jeremy Wariner on his 400m silver: "I'm disappointed. I had high hopes of regaining my title. I came off the turn in a good position and Merritt had a better finish. It's great having a rivalry like him because we give the crowd a good show."Fair play to Wariner. Honourable man. Decent chap.
2140: More tears, more American flags. The American relay team may not be happy at the moment (we are chasing further information) but Felix picks up her 200m gold medal. Huge huge smiles.
Merritt is delighted with his 400m gold medal: "It's not pressure. When I step on the track it's like clocking in. I got an A for my job! I came here with great confidence. We had a plan and I got on the track and executed it. It turned out well."
Tom Fordyce on Twitter in Berlin: "Could watch Allyson Felix running all day long - silky-smooth as Baileys on ice. Which as a man I never drink, obviously"
2132: Here's the reason why the US are disqualified from the 4x100m relay. Crawford passed baton to Patton past the allotted zone. The rulings state that the baton needs to be under control before the yellow line. And Steve Cram reveals that the error was not spotted by an official but the GB team complained. And Cram adds that the officials say the disqualification is final and the appeal won't be heard. That's what we've heard.
2127: HIGH JUMP GOLD GOES TO Rybakov with a leap of 2.32. Ioannou gets silver, Bednarek gets bronze alongside Spank. A lot of bad hair, a lot of screaming. Tremendous.
2125: Following news that the US relay team were disqualified, a spokesperson at the USA Track and Field confirms to BBC Sport they were disqualified and yes, they are appealing. We will keep you posted.
2118: "Nein nein nein nein" Raul Spank cries out. The German fails his leap as the men's high jump final gets super-tasty. It's down to four. Yaroslav Rybakov, Kyriakos Ioannou and Sylwester Bednarek also in the hunt for medals. Lot of screaming. Very noisy event this. And the crowd are loving it. Could go mental if Spank does something special in a minute. They're attempting 2.35m. Rybakov will win if nobody gets any higher.
From Emily in Bristol via text on 81111: "why do they compete in sunglasses when it's dark?! are the floodlights really that bright?!"
2111:NEWSFLASH: The US 4x100m relay team have been disqualified for stepping out of their lane, according to Hazel Irvine as the live TV coverage goes. Red button and website video still running. And I'm not leaving you until the last person in Berlin turns the lights out. More on this soon.
Allyson Felix, 200m champion: "I knew I was very strong and was able to power away. I wanted to represent my country well and make Jesse Owens proud."
From SportsUnited2009 on 606: "LaShawn Merrit did very well there. Bet Wariner's gutted. Thought Bingham could have got a bronze but it wasn't to be it seems."
2106: A really strong finish from Merritt there. Comfortable. Dominant. "It was all over from 200-300m. It was even with 200m to go. Merritt is strong and powerful and pulls away. Two years in row now. Bingham had a great race in the semis but can't do it here in the final," Michael Johnson says. Merritt wins in 44.06. Wariner second in 44.60. Bingham says: "It was hard running in lane eight. I didn't take advantage. I ran a terrible race."
2100: It's the 400m final. Wariner going for a hat-trick of world crowns. Can he do it? Renny Quow bursting with confidence. US-born but now Brit Michael Bingham (coached by Michael Johnson) looks nervous. On your marks. All part of the build-up isn't it. A lot of tight lycra out there on the track. LaShawn Merritt gets off to a great start. Chris Brown going well. Wariner kicks on. It's Merritt. A repeat of the 2008 Olympics. Bingham in seventh. Wariner crumbled a little under pressure there and he gets second.
From Gareth in Liverpool via text on 81111: "I am getting annoyed with British athletes saying things like 'it just didn't happen today'. Like it's out of their hands. I'd like to see them angry with themselves for not running their best. Do you think our attitude is a problem?"
From Macheda Stole My Hair Gel on 606: "400m final next, too easy to go for Wariner, I'll go for Merrit to annoy him again. Wariner silver, and bronze is open, Bingham an outside bet maybe?!"
2053: Emily Freeman, who runs 22.98, says: I enjoyed it. It was brilliant. Just a bit frustrated. It was such a big occasion. I don't think they got away from me that much."
2050: Emily Freeman in seventh. Felix looked like she was tightening a bit on the bend but what do I know. She stepped up three gears in the last 80m and Veronica Campbell-Brown (22.35) was really putting her under pressure. Her pace was too strong and she looked so comfortable. Three times world crowns in a row for Felix. Debbie Ferguson-McKenzie gets bronze.
2046: On your marks. Nervy times again. Those words always get me. Painted nails poised for action out of the blocks. 200m GOLD FOR ALLYSON FELIX IN 22.02
2044: Women's 200m final coming up. GB's Emily Freeman in the final. In lane two and facing some fierce runners. Can Felix win again?
2040: Rimmer is puffing and panting and struggling. Amine Laalou wins with Lopez in second with a brilliant diving finish over the line. Desperate stuff. Rimmer looked cream crackered. Will be interesting to see what he says about that one. He says: "It was tough. That was the best I could produce. I gave it my all - I just didn't have it on the day. I'm proud I got in good enough shape to be here but I just didn't have it."
From ShuBob on 606: "This three minute rule between posts does not help when commenting on LIVE events"Can I borrow your fingers?
2034: Rimmer up next in the last heat of the 800m. C'mon Michael my son. Up against David Rudisha who Steve Cram calls "brilliant".
2029: Another very fast 800m semi. Yusuf Kamel bursts through to win. Asbel Kiprop gets bumped and then gives up and falls to the back. Former Olympic champion Yuriy Borzakovskiy in second ahead of Alfred Kirwa Yego.
Tom Fordyce on Twitter in Berlin: "They have, you know - the crowd have sung him happy birthday! In English. Lovely little moment. Usain laps it up"
2022: Wipe-out. The 800m boys flew out and about five of them crash over each other. Abubaker Kaki in front and clips his own heel and he's over. Three of them go over. Wohhhh he goes sliding like a young duck on ice. The favourite is out of it. He's shaking his head and he's limping. His spikes are ripped to shreds. Still not sure if his heels were clipped. Nick Symmonds wins and Jackson Kivuva in second - they're the two automatic qualifiers. Thank you replays and Steve Cram. Kaki did trip himself. He just wasn't helped by a very slippery track. Shame.
2016: Men's 800m semis get going....Rimmer up in the third heat.
2013: Birthday boy is about to collect his present. They could have wrapped it. Yep, Usain Bolt strolls up for his 200m gold medal. Jamaican national anthem again. The German fans must know this one by now. Is that a tear in Bolt's eye? He's too cool to cry isn't he? He starts dancing on the podium and the smile returns. And he picks up a cheque the size of a bus for his world record. Oh lordy - the whole stadium are singing happy birthday. Nice touch. The whole crowd are loving that. Pictures time and he holds his fingers up behind bronze medallist Spearmon. Wallace has to slap him on the back to stop him! World records and putting a smile on everybody's faces. Brilliant.
2005: A right old tussle that one. 10 athletes still in contention on the final bend. Gelete Burka wins quite easily in the end but trouble for Langat. The Olympic champion falls over the line in seventh but I don't think it's enough. Then Mariem Alaoui Selsoui. Anna Willard close behind. Shannon Rowbury. Nuria Fernandez. The final is on the Sunday and Dobriskey has every chance of a medal.
From JackHughesByZola on 606: "Bit scrappy by Dobriskey - too much in and out of lanes - but she's through and that's all that matters."
1957: Second women's 1500m heat coming up. First heat round-up: Maryam Yusuf Jamal wins in 4:03.64. Natalia Rodriguez in second, Dobriskey third. American Christin Wurth-Thomas (the one who was 'believing' is fourth. Kalkidan Gezahegne is fifth. Others will have to wait. Here we go...Olympic champ Nancy Langat in this one.
1952: This can't be easy. Mervyn Luckwell has his last throw in the javelin. He's wearing a cap and booms one out but it's only 66m. Way below par and he's not through. He looks gutted.
1950: Dobriskey, tucked in nicely in the middle with hair flopping about like a horse's tail. That can't be easy running behind that. Good tactics maybe? Natalya Evdokimova takes an early lead. Dobriskey battling away and jumping about unsure about whether to go up the inside but has to settle for the outside. Now she goes inside again. The bell goes. Always makes my tummy flip that. She's going up and down through all her gears. She looks relaxed though. Top 5 to go through. Oooooh Dobriskey slips into seventh gear, moves up the outside and cruises down the straight to qualify comfortably. Good run. She twiddles with her necklace and looks a little unsure what to do with herself. relax Lisa. You've done well. Head for Phil Jones and say "anything can happen in the final". Maybe. Her eyes are the size of dinner plates. She's buzzing. She says: "I had too much respect last year and I enjoyed that race. Very pleased. It was shoving and pushing and I wanted to stay out of trouble. I'd love to improve on my fourth. it's been a difficult journey and I'd love to win a medal." Nice girl.
1944: World record broken - mine that is. For the 12 metre dash to the bathroom. Done well. I need an ice bath after that dash. On to Dobriskey. Track's dried out. No sign of Berlino although he raced an hour ago under the starts orders of Bolt. Nice. The American lady holds up her hand to show the word "BELIEVE" on her hand. Interesting. What do you believe in?
From Mad_for_Chelsea on 606: "that was pretty awful from jamaica, but they're through and with bolt and powell back will probably win the final"
1938: Lisa Dobriskey up in a bit in the 1500m semis.
1936: Third heat of the 4x100m. Jamaicans in this one. Plus Australia (don't mention the cricket), Thailand, Poland, Italy, and massive cheer for the German boys. First two to go through. France and Canada currently hold the fastest qualifying times. The GB boys can relax a bit. Jamaica looking a bit slow. Bolt will be urging these boys on. Italy through in 38.52 and big disappointment for the Germans. Dwight Thomas comes through with the Jamaicans second after a sloppy last changeover. Asafa Powell and Usain Bolt will be mighty relieved.
1931: American Trey Hardee is the decathlon world champion and gets his gold medal. US flags bouncing up and down everywhere. How white is his tracksuit top? Goodness only knows what temperature he'd wash that. I played for a football team and our brand new white kit was ruined after our striker washed them with a red shirt. Ruined after one game. We played in pink for the rest of the season. A shocker. Hardee punches the air. Two days of hard work - well worth it. Well done fella.
From Macheda Stole My Hair Gel on 606: "Britain looking strong, nice run from Ayreety, but think Williamson is the weak point, why can't the British Athletics Association swallow their pride and let Dwain back in? He could propel us into a medal position. US also good, Tremell lightning opening leg aswell!"
1925: "I'm very happy. I'm here to make up for the 100m," Simeon Williamson says. "We've got to get together as a team," Edgar says. "It's like being home" Edgar says about the weather. "Very nice" says Devonish. "It's an honour being part of the team," Akines-Aryeetey says. Jamaicans up next. No Bolt though. He's having a rest or just out for his birthday. Or both.
1922: Brits next to the champs the Americans. Canada in lane 1. Ghana. Portugal. Simeon Williamson leads off for the Brits in lane 6. Americans in lane 7. Then the Netherlands. Williamson starts well. Good change to Tyrone Edgar for GB. Marlon Devonish impressing. Harry Akines-Aryeetey storms down the straight behind Patton. He looked like a man pumped up - first bit of action for the young man who's built like a double garage. Impressive that. 37.97 for the American winners. "Devonish held his own against Crawford. Akines-Aryeetey would have passed Patton. Bodes well for both teams."
From clarke_j on 606: "This should be fun. The baton will be a bar of soap."
1914: How I love how Michael Johnson says "Batt-on". It's so not right but it's Johnson - it's got to be right. Hasn't it?
1912: ACTION AT LAST! With GB's boys in the second heat, we have the opening heat of the men's 4x100m relay. Who's in this one? Japan, France, Trinidad & Tobago, South Africa, Brazil, Switzerland..... first two go through and the fastest two. Slippy conditions. All seems smooth. French having a shocker. Trinidad & Tobago first in 38.47s and then Japan. Lemaitre puts in a cracking finish but the French are third and will have to wait. Brits up next....
1907: Didn't mention earlier. Another Brit in action later is Commonwealth champion Lisa Dobriskey, fourth in the Olympics last year. She runs in the 1500m semis at around 1940. "I'm not here just to make up the numbers," she says.
From RKW - Heart and Pole on 606: "You really do have to visit Berlin to feel the full force of the landmarks. It really is the greatest city I have ever visited - with an incredibly deep history. And on that note, I bid you farewell. Tschüs!"
Tom Fordyce on Twitter in Berlin: "Any ideas what we can get up to while the storm keeps the athletics on hold? Can you Tweet arm-wrestle?"
1858: TV pictures show the leaden Berlin skies above the stadium and they look as though a small child has painted all the clouds with bright orange. Weird. Revised timetable and only provisional so far. Everything's moved back 40 minutes. Men's high jump at 1900. Men's 100m relay heats from 1910. Women's discus final at 2000. Rimmer in the 800m semis at 2010. Women's 200m final at 2040. Men's 400m final at 2100.
1851: Quick round-up of the men's javelin qualification before it was held up by the wet stuff. GB's Mervyn Luckwell is struggling with a best throw of 65.02 and one throw remaining. Latvian Vadims Vasilevskis is the only man to have automatically qualified so far with 86.69m.
1849: Skies clearing slowly but still chucking down. Action expected in about 20 minutes. Women's discus final and men's high jump final coming up.
From anon. via text on 81111: "How can you all forget one event that usain bolt can do next. Long jump. Carl lewis did it and he was nowhere as quick"Long jump world record holder Mike Powell, whose 8.95m record has stood since the 1991 world champs, said earlier: "I can show him how to jump nine metres, for a small fee! With his height, he is the type who would scare me as a long jumper. He is tall and fast. You cannot put into words how great an athlete he is."
1840: A quick round-up of some of the action that happened before the clouds unleashed their tears on Berlin. Women's long jump - Naide Gomes, Maurren Higa Maggi, Nastassia Mironchyk, Teresa Dobija, Brianna Glenn, Shara Proctor all automatic qualifiers so far.
1832: Rain-watch. The action has been delayed due to an over-excited William Sharman running round the arena. No. Only joking. The rain is still falling and all athletes have been ordered off the track. Keep your thoughts coming in.
Tom Fordyce on Twitter in Berlin: "Absolutely smashing it down with rain in Berlin. The women's long jump qualifying has turned into a quicksand calamity - 3 athletes lost"
1824: Britain's Will Sharman, a classically trained pianist and fourth in last night's 110m hurdles final, is in the studio and recalls what it's like when he was racing in the stadium. "It's like when the Titanic comes into the harbour". Fair enough. Even Michael Johnson compliments the boy who can talk for the world: "You have an answer for everything. I love it. I love it," Johnson says.
1817:BBC public apology. We had problems with the sound of the video but we've assassinated the small gremlins and all is working again. Thanks for your patience.
1811: So bring it all on. All thoughts, predictions, German phrases (see 606 link) and ideas on mascots for London 2012 welcome. Even thoughts on where Berlino the Bear's career could be going next. 606 or text 81111.
1807: Weather watch and it's bucketing down in Berlin. Es regnet I believe it's called. The javelin qualification's been put on hold. Those relay boys had better find those rubber gloves or the baton could be slipping like an old piece of salmon.
1805: What's going on tonight then? Check out full timetable details. Women's long jump and men's javelin qualification continues including GB's Mervyn Luckwell. The men's high jump final begins at 1815 and then it's the men's 4x100m relay. GB's quartet go in the second heat alongside the US, with the Jamaicans (without birthday boy Usain Bolt) in the third heat. The women's discus final (1920) and then Brit Michael Rimmer aims for the 800m final. The night ends up with two crackers - Allyson Felix chases a third consecutive 200m crown (2000) and then world champ Jeremy Wariner races Olympic champion LaShawn Merritt in the 400m final (2020). Ich bin very very excited.BBC Coverage 1800-2030 on BBC Two/Online/BBC HD/ Radio 5 live sports extra.
1755: How can I possibly begin today without throwing a whole bag of furry giggles right at your face? All thanks to a 7-foot high little fella called Berlino who's taking the World Championships by storm. Watch the antics of Usain Bolt's new best friend right now. Any suggestions for 2012's mascot? London chief Lord Seb Coe will be reading this I'm sure so let's have it. Live video of tonight's action kicks off at 1800 by the way.