Unless you've been living in a cave for the last few years, you know what Twitter is - a free online service that allows users to send out concise, real-time updates on what they're doing at any given moment.
[...] The really good stuff, though, is hidden behind the scenes. Like many Web 2.0 applications, Twitter exposes its innards to the public via a REST API, making it possible to develop customized applications that run on top of the base service. [...] This article focuses on one such library, the PEAR Services_Twitter library, which provides a full-featured API for interacting with the Twitter service through a PHP application.
Once the package is fetched (via the "pear" command on the command line) he shows how to make some example connections like grabbing the most recent status for a user, updating that status, grabbing recent posts from a user's timeline, finding followers/friends and much more. The package makes it so simple that any one of these examples isn't much more that seven or eight lines long.