This is an excellent thread. CosmoGTD, I think you've really nailed precisely the problem I've always had implementing whatever personal development / organizational improvement / efficiency system I've tried. I procrastinate like mad, I'm perfectionistic, I doubt my ability, I fear success, etc. It's easy to make list after list after list and fantasize about how all this will help me clarify values and so on, but the rubber hits the road at the point where "DO IT" becomes "DOING IT." It is that moment where I usually find myself suddenly drawn to Web surfing, or working on a "more urgent" (read: less scary) project. What I have been looking for is a gentle way to PYA, because I find that if I think of it as an authoritarian "just do it" command, then I am more likely to resist it, even (especially) if it is wholly internal, unrelated to externally imposed requirements and deadlines.
This is particularly important in my current job, which requires that I be highly self-motivated, generate my own work, and work without external deadlines. GTD has been a godsend because it's helped me simplify my systems and focus on the lower level. But I still get stuck on "DO IT."
I hope that others will continue to chime in with their own experiences in this thread.