I have been a GTD wannabe for a long time. I still am a relative newbie on it, and my method isn't going to work for everyone, but now that I am investing a *little* more time into it, I am discovering just how much I love Natara Bonsai (not connected to the company in any way, shape or form; just a pleased customer).
It just works very well for me, especially since hitting upon the simple little idea of using the red outline entries to "schedule" (screenshot).
Oh, to have this on a good mobile smartphone and sync to the web.
Palm T|E; Win XP