I'm starting GTD. One step I've taken is simply carrying a paper 3"x5" pocket notebook on me. Just jotting down "in" as it pops into my brain is already stress-reducing.
The problem I'm encountering is having something to write with! I typically don't wear shirts with pockets. I find it easy to keep the small notebook in my pants pocket, but a regular sized ballpoint pen isn't pants-pocket friendly. Where can I get pens that are no longer than a car key? I checked Staples, but no luck. Little golf pencils don't appeal to me -- really looking for a pen.