Reader BishKopt writes in with his ubergeeky system for getting things done with a simple text file format and a script that parses items into separate contexts.
His system works by entering all of your actionable items into a projects.txt file, following a specific format that indicates whether an item is a next action, the context of the item, or marking the items as complete. Once you've added all your projects into the file, you can launch the included AutoHotkey script for Windows users, or use the included perl script for any other platform, which will parse out the project list and generate separate to-do lists for each context—and re-generate them each time the projects file is changed.
Once you've got the separate lists, you can simply refer to the lists by context. While this system might not be right for everybody, it's an impressively geeky way to keep your to-do lists organised.