2010 update: Ever ready to tinker with organization schemes, I’ve done some adaptation of the Journal and Tasks bundles for TextMate to produce another, very very lightweight way to implement a Getting Things Done routine in Textmate. Check out the JournalTasks bundle if you’re so inclined.
Haris Skiadas, who has made massive contributions to writing in LaTeX with TextMate (see for example his screencasts of good use of the LaTeX bundle), has put together a super TextMate GTD bundle. Haris has been hacking on it nearly-continously for several days — I confess to having harassed him significantly throughout development so far — and the bundle is a fully-capable GTD system: You can work with a single document, or as many as you want, can easily move projects around, add tasks, and add and modify contexts. The bundle has a number of commands to generate Next Actions lists, and it will archive completed tasks/projects to a separate log file.
Up until now, I’ve been using the Kinkless GTD system. Lately, however, that software began to feel a little cumbersome, a little too cognitively heavy and opaque. Since it lives in TextMate, Haris’s GTD bundle works with pure text, making highly extensible, and it works great (it even knows how to convert your Kinkless document to its own format). Today Haris capped it off with a script that filters an inbox (fed via Quicksilver) into your GTD documents. Seriously cool. I highly recommend giving it a try if you’re using either TextMate or GTD (or need an excuse to give either one a test drive).