Simple LinkedIn PHP is a library for interacting with the LinkedIn API. The library was designed and tested for PHP 5.2+ and is not expected to work with PHP 4. The only prerequisite for Simple LinkedIn PHP is the PHP cURL library.
Glympse, a service that allows GPS-enabled mobile phone users to temporarily share their location in real-time, has announced the availability of the Glympse platform allowing developers the ability to integrate real-time, temporary location sharing into third-party web and mobile applications. Glympse has also made available SDKs for iOS and Android as well as REST based APIs for use in websites and web based applications.
Hellotxt, the service that lets you simultaneously update your status and read your friends' status across many services, has now released an API. There is a long list of microblogging and social networking sites that Hellotxt interacts with, ranging from Facebook and LinkedIn to of course Twitter and FriendFeed (see their home page below).