Foursquare Lets Others Play With Its API

Up until now, Foursquare, the hot location-based service, has only let a handful of developers play around with its API. Starting today, the company is formally unveiling it, hoping that a robust app community will form around their data.
Here’s the way they’re describing it:
The foursquare API enables developers to build applications that interact with the foursquare platform. You can use the API to create new ways to check-in to foursquare or visualize the data generated by the foursquare community.  Our API is still a work in progress and we look forward to your feedback and suggestions!

In announcing the API, Foursquare has also created an app gallery to show what’s already been built ontop of the API so far. Included in this gallery are:

Foursquare Android, the open-source Android app (our coverage here)
SocialGreat, a venue popularity tracker (our coverage here)
MobZombies, a location-based Zombie check-in game
PeekMaps, a way to view your friends on a map on Peek Mobile devices
FourTap, links London subway card swipes with Foursquare data
YipIt, a way to find nearby deals in New York
A Foursquare WordPress plugin
Ul.timate.info, a way to send geo updates to Firefox
Last Night’s Checkins, a diary-creator for your Foursquare checkin history

Another third-party app just announced is Layar with support for Foursquare. The augmented reality browser has a new beta version with functionality that allows you to use your mobile device to look around and see Foursquare venues around you. You don’t even have to have an account with Foursquare for this to work, so it seems like it could be a good way to convince new users to sign up. If you do have an account, you can checkin to venues right from within Layar.
That’s a pretty good list of third-party support considering that access to the API has been very restricted up until this point. The opening