Howard Abrams is rethinking his GTD workflow and has written a three part post that describes his evolving scheme. The first part is here; there are links to the next part in each post.
The basic idea is that every new task or idea is initially put, as an Org file subtree, into an inbox that he reviews everyday. Upon review, each item is moved to an intermediate destination that reflects its status. For example, items that can be acted on immediately are placed in his task file; items that are more complicated to complete are placed in a project file. Similarly, reference material is filed away in an appropriate file. The exact scheme is shown schematically in his second post. Finally, when a task is completed it is archived in his journal.
As you can see, there’s a lot of data moving involved with all this so Abrams has written several helper functions to easily move the Org subtrees among the various files that make up his taxonomy.
Not everyone is a GTD adherent, of course, but if you use Org-mode to track and schedule your tasks and ideas, Abrams’ post has a lot of good ideas that you may find useful. He’s made the code easy to understand and modify so you can directly use some of his helper functions if they fit in with your workflow.
As always with Abrams’ posts, there’s a lot of good ideas worth stealing in the post so you should definitely take a look.