He saved about .02 just from his reaction time. The wind helped him out another 0.4 seconds. And back to the scary part, some analysts are saying, while his technique has improved, he still has much to go in the first 30m of the race and was the worst technically in this race. Scary indeed!
He averages over 23 mph. My estimated top speed is about 23.5 (avg 19.96). Dang dang, that'll make ya feel slow!
Edit: Breakdown and comparison to Beijing: http://speedendurance.com/2009/08/17...he-run-faster/