Chris at Trichech.us has written up a short guide (and included a useful little AppleScript) on how to run GTD in VoodooPad, the get-it-down quick application that we love so much here at TUAW.
Basically it revolves around a series of tags-- if you have a task that needs to be done in a certain context (such as home or office, or even as specific as "at the computer" or as general as "thinking"), you just tag it with @ and then whatever the tag is. When the script is run, it grabs all of the tagged lines, and combines them all on one page, so you have an at-a-glance look at what needs to be done where. And you can even date items, and see them placed on the "Actions" page as well.
The big problem with me and any GTD plan is just that I tend to be so picky-- if a system doesn't work exactly the way I want it to, I tend to get lazy and start ditching it for good old pen and paper again (which causes me to fall back into the same old gaps). But Chris' system looks solid enough to use without a lot of configuration, and yet adaptable enough that I can shape it to my own mind. If you've got VoodooPad (and if you don't, why not) and you're on the hunt for a GTD system, give it a try.
[ via Gus Mueller ]