If you're anything like me, you have way too much e-mail to read it all.  To try to cope with this, I've resorted to a collection of rules that sorts my mail into a Byzantine structure of folders.  This helps a little, but has the problem of helping me miss a lot of mail as well.  Things get neatly sorted into specific folders where they are summarily ignored for large periods of time.  I just ran across a talk by Merlin Mann discussing a concept he calls "Inbox Zero."  There are basically two main concepts:

1. Don't let e-mail run your life.  Check it only periodically.
2. When you do check it, take action on each piece of mail right away.  The key is the nature of the action taken.  In my world, taking action has always meant reading and responding to the mail.  This takes a long time and it's hard to get through the mailbox this way.  Instead, Merlin suggests doing one of the following, all of which are quick:
1. Delete.  If the mail isn't important, delete it immediately.
2. Archive.  If this isn't something you need now but might want later, move it to an archive folder.  He says to use just one.  That way you don't need to think about how to file it.  In Outlook 2007 (or earlier if you used desktop search or Lookout) and online mail programs, searching can solve the problem folders were intended to solve.  The advantage of only one is that you don't need to think about how to file it.
3. Respond Quickly.  If you can answer in 1-5 sentences, just do it.  Then delete (or archive) the mail.
4. Just Do It.  If action is required that can be done now, get up and do it.
5. Flag For Follow-up.  If the mail requires more time, move it to a follow-up folder or mark in such a way that you know to get back to it.  This lets you move on.  Come back to this folder at the end of the day and clean it out.

That's all.  I'm going to give it a shot and see how it works.

Apparently this talk was based on a series of blog posts.