Though I am late to this game, I have started playing foursquare. I tried to get into it a few times, but since I don't carry an iPhone, the web UI always turned me off. But Eric showed me the mobile web UI a few days ago and that works well for me.
For those who don't know, Foursquare is a game about "checking into" places you are physically at. The game play is light but fun nonetheless. You get points and badges as you check into more places. I'm a big believer in the power of game play to encourage users to engage more frequently with a service.
Foursquare is delicious for places. It's a dead simple way to record where you've been, and if you feel like it, what you thought of it. I like that idea and that's why I am going to play foursquare.
I am also very encouraged by the fact that, like Twitter, Foursquare has an API that allows any developer to build a Foursquare app. I hereby request a slick Blackberry app. What I'd really like is a mobile app that would allow me to check into foursquare and also check in with Twitter. I'd be all set then.
This is my profile. I'm just getting started. I am going to use the Facebook rule in terms of friends. I am only going to friend people I actually know and would likely go out to dinner with. So if you request me and I don't accept, please don't get upset.