The LinkedIn-API-JSON-Client is a Python library for interacting with the LinkedIn API. The library is designed to allow developers who don't understand either OAuth or the details of the client library to make use of the API.
Gowalla, Foursquare, Yelp, Facebook Places, the list goes on. There's certainly no shortage of methods to tell people where you are and what you're doing while you're there. Startup Whatser, built on the SoGeo API for location-based apps, has jumped into the ring with a different approach to check-in services: to be useful.
After four months, Facebook is set to open its timeline actions to developers this week, according to AllThingsD. The feature is an addition to the Facebook Graph API that allows developers to assign verbs for actions users perform within applications. For example, how users now "like" things, they'll also be able to "read" articles, "play" games and "listen" to music. I would expect many, many actions to be submitted to Facebook for approval, especially related to game-specific acts. It's too early to tell how closely the social network will watch its pending list of actions, though there's a clear approval process.