I'm not sure if this has been discussed already as it seems such a no brainer now I've hit on it. I have been doing GTD for over 3 years but it seems I overlooked this.
I've been using Outlook and Palm for my lists for most of the 3 years but have recently been developing resistance to keeping my project list up to date. Perhaps because I have learnt to think of follow on actions when an action is completed but also because I have always found the toing and froing from action list to project list cumbersome and frustrating in digital.
I've now hit on the what now appears obvious solution (maybe it always was and I was resistant to the idea before) of having the action list in digital but the project lists (and also a prompt list and area of focus list on paper).
To me this has the following advantages:
1) Action lists are constantly changing so I have always got frustrated listing out actions on a new sheet of paper usually on a daily basis. So actions are best for me on digital.
2) Project lists change less frequently and in fact the action of writing them out again in a weekly review helps one define them further if necessary.
3) In a weekly review one has to check each project has an action. This is very easy if you can check a piece of paper but then look for actions in different context lists on a digital system. In a sense it a solution to the digital solution I have long wanted - to be able to look at the project list and action list in separate concurrent windows.