Adium Status Plugin
Adium was a multi-protocol chat client for Mac OS. I enjoyed it because it let me connect to AIM, Google Talk, ICQ, and other popular chat clients from the early/mid-2000s.
Shortly after getting Adium I installed a TwitterAdium plugin (aka Xtra) that would set my current status to whatever my most recent tweet was. The problem that I had with this plugin was that I had too many apps hooked to my Twitter account and was running into rate limiting issues on their API. I had derek.broox.com, Facebook, MySpace, and Adium all hitting Twitter, which made them sad.
Since derek.broox.com grabbed and cached my Twitter status, I decided to be nicer to Twitter and write an Adium plugin to grab my status from derek.broox.com.
I built the plugin with Ruby and made it configurable via YAML. I simply defined the url and duration in the included YAML file and set my Adium status to %_RemoteStatus. That would then periodically hit my website to fetch my status and allow all of my chat contacts to follow what I was doing while I was on the go.