I have to agree with Alan. I "created" my system from scratch using paper, ran with that for about a month, and then got everything streamlined onto my Palm ("vanilla only please").
In the beginning, as I was starting from scratch with GTD, I had no idea how it would function (and I am sure many people have been surprised to find out that GTD had a life of its own. It is almost a living thing) and many of the processes I developed happened almost by themselves. I think doing it on paper in the beginning slows the process down a little bit and naturally forces you into a pace that is reasonable.
I know far too many people who get obsessed by "I need to get Palm program "X" to export to my To-Do list and then properly update through the desktop conduit". That is fine for later (or maybe never) but in the meantime concentrate on getting your system on track.