December 9, 2003: This has been written about to death, but I really think email clients need to be organized around faceted classification. It's actually surprising given how data and context rich emails are that email clients have lagged behind photo and audio file browsers in the sophistication of their classification schemes.

Search (across and within mail folders) is a major improvement, but it sure would be helpful to assign keywords to individual messages and then be able to filter by keyword or date or author etc (and the distinction between filter and sort is an important one). Mike's slider idea and interfaces like this make so much sense for email. I assume someone will email me a link to Lifestreams, but I've always been turned off by the way Lifestreams privileges Date over other organizing principles (although it probably makes more sense for email than other types of documents). There are other projects, but still I'm using folders within folders to manage most of my documents.

This is not to say that I see this as a lost cause; it's easy to see that metadata-organized file browsing is around the corner. I think I'm just surprised how far behind the major email clients are.

Update: Thanks to Andrew for the link to Remail, a next-gen email project out of IBM. While many of the ideas (e.g. threads) have surfaced elsewhere, I haven't seen anything like Remail's Thread Arcs feature. I also like that it can incorporate RSS feeds. And, as expected, there's a faceted classification mechanism called Collections.