I have to admit that foursquare.com is one of those social media trends that I just can't get excited about. For one thing, I'm a bit of a privacy-control freak, and really don't want most people to know exactly where I am most of the time (as if they even cared). For another, I'm already active on other sites. But foursquare.com is getting too big to completely ignore.
To me, this seems a lot like just signing up for spam, but I was encouraged to see that there's an Android app, just in case I do, indeed want to get some of that spam. (Yeah, I like my Droid.) But I'll let you see for yourself. Here's a video explaining how the service works.