Today at an event in Palo Alto, CA, Facebook unveiled its new "Facebook Places" product — essentially their check-in utility. Representatives from Gowalla and Foursquare were invited to take the stage at the event to talk about how they plan to leverage Facebook's new Places API. Both will allow you to check-in and publish the data to your Facebook feed. Your badges and pins from each of those apps will transfer over as well. As we expected, Facebook is playing nice with these guys — and they're clearly excited to play nicely back given Facebook's 500 million users.
Yelp and Booyah (maker of MyTown) are also launch partners for this new API. Booyah is actually making a new app called "InCrowd" build on Places API. With Yelp, you'll be able to transfer your check-ins both to and from Facebook as well. One interesting thing Facebook brought up is the ability to quickly tag venues you find to save for later. This's expected to launch soon as a new feature.
Facebook says the Places read API will be available tomorrow. Meanwhile a write & search Places API is in closed beta.