All right, I admit it - I'm a Foursquare addict (and a chocaholic-but I cannot do anything about that). Foursquare is primarily for letting your friends know where you are and figuring out where they are. Secondarily, it's for collecting points, prize "badges," and eventually, coupons, for going about your everyday business.
And it's popular. At February 21, 2011 Foursquare crossed 7 million users IDs!! I'm one of those 7 million and here is my confession:
You make up reasons to go out and check in
You study ways to get badges
You know how to maximize your checkins
You figure out how NOT to get the "Whoa" message
You follow Foursquare/AboutFoursquare on Twitter to get the "latest news"
You submit issues to 4sq help desk
You categorize venues to earn badges
You add venues to get more points
You watch the leaderboard in your area
Wish you could have attended "hackathon"
Look forward to "anniversary" to be able to create Infograph
You structure your day around foursquare.
I just checked my "stats". Been out 292 days (73 to go until my 1st anniversary) with over 4000 checkins. I just added a countdown so that my Infograph will be posted here! LOL - gotta get a life!