Here's a nice tool that Hanselman turned me onto a few weeks back.  SpeedFiler, has literally made my inbox management so much easier.  My inbox is now at zero at the end of nearly every day.  I've been slowly incorporating GTD into my life and have started with my email handling system.  Every email that comes in gets processed quickly or filed away for future consideration into the proper folder.   SpeedFiler assists with that, improving upon Outlooks standard move to folder tool by allowing you to find a folder in a short time, allowing for very speedy filing.  Read Scott's entry as he shows screenshots and gives more details.  I just wanted to give a little bit of promotion for this great tool.

Just for the record, this was an unsolicited endorsement and I have just purchased SpeedFiler no more than 10 minutes ago after a few weeks with the trial version.  I'm not affiliated with the Claritude Software in any way.