It’s been over 2 months since Foursquare launched at SXSW and something strange is happening: My friends are still using it — a lot. Sure, for the service to have real success, it will have to spread well beyond pockets of tech hipsters, but even this success is something we haven’t seen with the majority of location-based social networks so far. But Foursquare’s strategy is smart in that it’s just as much of a game, in which you collect badges and gain mayorships of your favorite local places, as anything else. And now it’s gearing up for a further expansion with an API.

Initially, team hopes this API will be used to build more mobile clients, co-founder Dennis Crowley tells us. Right now, there is only a native app for the iPhone, but he says that there are already a few people working on a native Android app as well. And they envision someone building a BlackBerry app shortly as well. I know that will be music the ears of a lot of my friends who are forced to visit Foursquare’s website from their mobile browsers, which is a less than ideal experience right now.

Crowley also says that someone has already used the APIs to build a desktop client on Adobe AIR.

As for the iPhone app, version 1.2 has just been submitted for approval to the App Store. As we know, that’s always a crapshoot, but assuming it gets approved in relatively short order, there will be a lot more cities the service will be available in. The team also recently rolled out a way to submit your own badges.

But the recent news that most interests me has to be how some cities have establishments that are acknowledging mayorships. You can a mayorship in Foursquare basically by being the person who checks in there most often (on different days). One bar in LA, Good Hurt, is giving away a free beer to the “mayor” every time they come in! Another place in Denver is giving away free lunches to the mayor, and some bar in Brooklyn has a blackboard which they write the mayor’s name on, Crowley tells us.

He says that the team is thinking about ways to work with more establishments to offer these sorts of deals. It’s really a pretty ingenious idea for both the service and the establishment, as it drives usage of both. It’s sort of like what some brands are using Twitter for, but the location aspect is particularly interesting and could be much more targeted. And yes, that could even eventually blossom into business model.

But basically, I just want some San Francisco bars to acknowledge my mayorships and give me a free beer. That’s my business model.

[photo: flickr/a4gpa]