VersionTracker spat out a pair of interesting extensions to Mail.app today:
Mail Act-On provides a cheap way to file mails with a quick keystroke combination, sparing people the pain of AppleScripting something for themselves. The obvious application for GTD people is pointed out by the author himself: Creating Act/Hold/Respond/Wait/Someday folders and filing to them as appropriate.
Aaron Swartz has shown how to do this with AppleScript … Mail Act-On is more pointy-clicky, and it uses the already friendly and useful Mail.app rules interface to do its thing, so there’s less learning curve.
The other nugget is from the same developer:
MailTags brings metadata to individual mail messages, so some additional criteria can be picked up by Smart Folders, basic Spotlight searches, etc. It adds the ability to add deadlines, change message priorities, and assign messages to specific projects.