I found this scan of a nice speed feat on comicboards a while ago (credit goes to Zeeder btw). I had never seen it before and I found it pretty interesting:
http://img323.imageshack.us/img323/6548/hulksuperspeedbj7.jpg
I’ll quote the source of the scan also, since Zeeder actually does the calculations of how fast Hulk’s speed is here:
"The Hulk has banner's brain due to Modoks attacks. Modok has a virus. In order to make the antidote, the vials must be placed in a centrifuge for 40 hours at 40,000 rpm's.
You can buy a centrifuge online that does 6000 rpm and produces 6000 g's. The comic centrifuge would be doing about 12000 g's easily.
The Hulk does in 8 minutes, what the centrifuge would do in 40 hours. He would be producing 6 million 500 thousand(6,500,000) g's. His hands would have to vibrate at 1/9 the speed of light.
He does it with strength. He isn't even mad."