This is another meme, but I think it is an interesting one.
A bunch of grad students are doing an experiment to see how fast memes travel throughout the Internet and how willing folks are to "sign up" for a game. In order to 'play', you need to get an invite.
Consider yourself officially invited! If you follow the link, I gain points and the points trickle up to the person that invited me and so on. I'm not so interested in the points as to seeing what these researchers come up with. They don't require an email address (no chance to receive spam) and if you 'sign up' and update your own profile with a location, I will be able to see it on a map... and people who get invited by you and put their locations up, you'll see them on your map.
Enjoy!