I also want to point out that it is easy to waste a lot of time looking for the absolute best productivity solution. The reason I picked GTD is because it seemed reasonable and other people claimed success with it; I didn't want to waste a ton of time evaluating methodologies. Similarly, there are a lot of productivity tools (especially software); I spent WAY too much time evaluating them, but only because each of them suck in their own special way. I think now I'm simply going to use Outlook 2003; I can't access it from the internet but I can sync with my phone which in many ways is even better.
(1) Less UI clutter, (2) instant response time, (3) automatic Bluetooth sync with my phone, (4) offline ability (I live in Thailand and my internet connection is not 100% reliable), (5) an easy way to get stuff from my email to my TODO list, and (6) instantly-responding UI.
I like a lot of things about Nozbe.com but it is too slow and I cannot do anything with it using my phone. Also, the fact that you will have to pay according to how many "projects" you have is crazy.
