Wow, I've seen noprocrast dozens of times but never thought to use it. Now that I've looked into it, it's actually a fantastic model (maxvisit and minaway). Not hard to comprehend, but if anybody's curious:

http://ycombinator.com/newsnews.html#07nov07

I wonder if there are any chrome extensions that share a similar model.. I use 'stayfocusd' right now, but it's nowhere near as effective.