I'm going to give the 3x5 index card method a trial from 9/16/05 through 10/15/05. Here's how I'm using it:
The basic card layout
(see attached image below)
Parent-goal-or-project is the project that spawned this Next Action, or the Goal that spawned this Project.
@context is the GTD context in which this action can be done ('Project' if a Project)
mm/dd/yy is the creation date of this card.
PDA Cards
(see attached image below)
Contexts
Computer
Agenda
Projects
Someone's Name - Awaiting
Someone's Name - Agenda
Home
Office
Someday/Maybe
I do not have a someday/maybe context. Actions/projects that are someday/maybe go into a someday/maybe envelope, but they are marked with their normal context.