smorton: GTD-PHP is a free, open-source package that you can run on your own or a hosted web server, that implements the GTD system for you. It works in PHP and MySQL (each in version 4.1+ or 5.x). However, if pen & paper works for you, then I'd say stick with it.

MarinaMartin - are hierarchical actions dealt with in the GTD book? I don't recall it, at the moment. But if you have a lot of complex dependencies, you may need some full-on project management software such as Primavera. However, to use your less complex example: 'Paint the room' is the project. This project has 3 next actions:

1. calculate total area of room

2. pick a paint colour

(assuming that those two are genuinely next actions, and you don't have other things to do first, such as buying a tape measure, or getting some sample pots).

3. buy roller, masking tape, trays.

The project will also have actions which are not yet next actions, but which you wish to record in the system: "don the overalls and paint the room". And before that, perhaps you are going to "phone a friend to ask them to come round to help" - you won't do that until you've got all the bits, and are ready to paint. So, that's an action, but it's not a next action. If the GTD software allows you to review all your actions (next-action or otherwise), when you complete the current next action, would that meet your needs?

Within GTD, you might have inter-project dependencies: one project contributes to another, which feeds into yet another project, and so forth: within GTD, that's normally accounted for within the "10,000 feet view", or similar. Gtd-php does allow you to track these dependency relationships between projects.

If you feel that the current gtd-php (v0.8 beta), doesn't maintain project-, waiting on-, and next action- lists correctly, please let the team know where it fails, and I'll see what we can do to get it fixed.

Regards,
Andrew