In playing with my new iPod and looking for interesting podcasts, I discovered that Merlin Mann at 43 folders does one. He has a series of interviews with David Allen of Getting Things Done, including Productive Talk #05 on Email and making sure the system works, no matter what.
The quick version is that e-mail is just like anything else that we let enter our lives. If we don't deal with it appropriately (delete, delegate, archive, do now, do later), it will overwhelm just like that pile of unread magazines or interesting articles. For email, the inbox is supposed to be processed (empty) at the end of the day.
David Allen's perspective on Blackberry devices is that they are evidence of a poor system for dealing with email, so the users find themselves attached to the email rather than the system. The hilarious part of this was the suggestion that in three years people are going to move from the Blackberry to the Watermelon because they need a bigger place to deal with their broken e-mail management system.