Facebook just shot another missle at Foursquare.
It announced that it was opening up its location API so that developers can now send check-ins to Facebook Places from third-party applications.
(The API used to be read-only.)
Opening up the API, Facebook moves closer to getting its location services into all relevant mobile apps.
The unspoken message to Foursquare was clear: We’re the platform and you are the single feature application.