This unofficial Twitter Ruby gem is in its 5th version, and is heavily supported with documentation and code examples. Twitter Ruby Gem allows users to follow a user, retrieve a user name, fetch a timeline of tweets by a user, and many other functions. In this version of the gem, Twitter Streaming API is also experimentally supported.
For music enthusiasts who thrive on insider knowledge and detailed music conversation, WhoSampled would be just their cup of tea. It's basically an online community for discovering and discussing sampled music, remixes and cover songs. WhoSampled has partnered with The Echo Nest to provide the WhoSampled API that allows developers to access and integrate its functionality with other applications.
As a developer, you can figure out how to make your program connect to Facebook, Twitter, SMS, and Email. Or you can use the Embarke API and connect just to Embarke, a messaging platform that connects you to them all. You can skip learning the specifics of how to connect to each of them. The REST API's website has a five minute tutorial video on how to use this gateway to its developer tools for social communications.