I have recently returned to an oft-delayed task of putting my personal GTD plan into action (there is something almost zen about that now that I think about it...) and it seems like the first major decision you have to make is what particular tools to apply to the task.
Since I tend to live in email I bit the bullet and moved over to Thunderbird so that I would have the same client on both my Mac and PC (if you have the luxury of being Mac-only then just pop over to 43 folders and read through the tips there...) Next up was to google around for Thunderbird + GTD and pick up a quick set of suggestions from a couple of blogs on how to use labels, filters, and a few extensions to get things under control.
I can't say yet if this is going to be the best path or one that I would suggest to you, but one point in favor of using your email inbox to run your GTD system is that the basic tools are omni-present. If I need to add a new item to the queue I can email it to myself from my Treo while on-the-go and various mail clients that can hit my IMAP mailbox give me the ability to update things from wherever I happen to be.
Good luck, and please continue to share any cool tips or insights you discover while setting up your own system.
The email thing is compelling, because there's no way I can move email tasks out of email (just too much work and shuffling around to make the physical move), but it's relatively easy to move things into email. The only problem is the interface... but maybe with a little procmail, some client extensions, and some scripts (e.g., a script to add a task, which needn't be as complicated as opening a new email typing my name into the address and all that)... that might work sufficiently.
This post seems to be the best summary of a labeling method for Thunderbird. I like that it uses labels even for things Thunderbird does natively (like deletion), because in my experience some operations (like delete or moving folders) require just a little bit more time to process (say, 0.5 seconds) that slows me down. Flagging and operating en masse after the processing is done will give that little speed boost that I know I'll appreciate.
todo.sh looks interesting, but I don't know how important I'd find some of its features. Specifically, managing a list through the command line seems a little crude. I think just being able to send messages into the system without using a mail client will be sufficient for me.# Ian Bicking