My GTD system is a 3 tier system at the moment.
I have a dual monitor PC running Outlook 2007 (this is recent, it was outlook 2003 for a long time prior to my recent virus issues), a 4 drawer ancient metal file cabinet that was drawn out of hell (I need a nice expensive wooden one) and a metal side opening inbox which is ok (but I would like a nice wooden one here too). I file with a Brother label maker, manillla file folders (smushed into my crappy file cabinet with book ends) and capture on a yellow memo pad and index cards.
I sync outlook to a blackberry curve. I use the blackberry for processing, capture (This works pretty well and I am adamant to stick with it). The greatest thing about the blackberry is I can mobile blog with e-mail and take little pictures of things that amuse me (a cool way to capture too).
Dual monitor running Outlook 2003, a file drawer and a OLGA 4 drawer side opening cabinet, 1 folder per hanging file of course labeled with a Brother label maker. My inbox is a fake leather bound front opening inbox which I freakin love but it is wearing pretty bad. At work I capture on index cards while walking the floor and a memopad at my desk.