The site is pretty much being hammered from a BoingBoing mention, but it's a pretty cool "Passively Multiplayer Online Game". Essentially, you get points and accrue resources by browsing the web. It's a Firefox toolbar-based game, so no IE allowed, i guess.
Check it out here: PMOG (http://pmog.com)
and yes, i've already created a Mission (http://pmog.com/missions/pen_and_paper_roleplaying_tour). to help spread the word. ;)
I tried it briefly, but I think it doesn't work right with Firefox 3, and honestly, it was all just too distracting.