In his latest post, Cole ponders the inbox-zero concept. I have been trying to work with an inbox of zero since around January, mostly with success. I think the more email heavy your life is, the more important it is to practice some kind of inbox-zero system.
Intranet collaboration tools can help get archival information out of our inboxes where they cry for attention they don't need while providing a common, shared repository. But I don't know if communication tools like blogs/wikis/etc can save us totally from information overload. We need to develop personal strategies for dealing with the information flow intelligently. Merlin Mann calls his inbox-zero presentation "advanced common sense", but it is worth a look. It is basically a boiled down version of GTD.
I was able to go from about 3500 emails today down to 1000 -- a far cry from zero. It is a start. I've also recently simplified my use of MailTags in Apple Mail. I now typically only use the "Follow up" tag to highlight important or actionable emails. Some do slip through the cracks though.