Google’s Gmail lets you create custom labels for tagging any of your messages. This seems ready-made for a Getting Things Done implementation.

Your “INBOX” holds your unprocessed mail, while your processed messages are manually shuttled into the appropriate buckets. All that processed mail lives in the same archive, but you use your custom Gmail labels as GTD “facets” to quickly pull up just the messages you need for your current context.

Plus, of course, you can “Google” your own mail archive with the program’s excellent, advanced searching options. Believe me, this will soon have you wishing every mail program’s searching was this robust (I’m looking at you, Mail.app).

Anyone out there tried a Gmail implementation of GTD yet?