A lot can be learnt about implementing GTD by reading stories of how other people have done it. Please add a page to describe your implementation.
I have written about some specific aspects of my GTD implementation on my CharlesGTD Blog, but in a nutshell, I use a plain paper system. I maintain a text file on my Windows home computer of projects, and next action tasks. I print out lists of Next Actions by context and keep these in my Day Timer ring binder. The ring binder/day planner has the calendar with a week to an opening in one section, the Next Action lists in another section, and more sections of plain paper and graph paper for idea capture. I also carry 3 x 5 system cards for idea capture. Paper is easy, cheap and portable!
This is an article I first wrote for Blackbelt Productivity where I describe my life pre-GTD, my implementation and my post-GTD nirvana! This is a slight oxymoron as I don't believe even DA has reach this state so what chance is there for us mortals! Have a read and see what you can use.