The goal: get someone to look something up on Wikipedia.
How you do it: by being sneaky. Talk about some obscure topic, or figure out how to drag a conversation in such a way that somebody WILL end up on wikipedia. Like, if you're all talking about lunch, you can say "Didn't McDonald's used to have a hamburger that came in a two-sided Styrofoam package, so the cold stuff stay cold? Man I bet there's a whole list of discontinued McDonald's foods somewhere." Then just stare off, continue to work at your desk for best results as if you're NOT EVEN THINKING ABOUT IT.
This works best in a group. It's still fun with people who know about the game, because then the real challenge comes up... if you can think of something that will get a guy to wikipedia even when he knows it's a disgrace to his game record, you're a real winner.
When you do catch someone on wikipedia, you criticize them for not being productive and gloat about how focused you are. Which is another reason why now's a great time to play this game, I don't know about you but where I work we're horribly understaffed because we can't afford to hire people, so we're all trying to get work done... which makes distracting someone feel like more of an accomplishment.
Also... bonus points are awarded for just how non-work-related you can get to. Get someone on wikipedia reading about how to set up a new ms outlook folder and that's not very impressive. Get someone on there reading Britney news, go you. If they're at a not-work-safe article, I think that's the top prize... but we have yet to see this.