Sometimes when I'm scanning an email archive, it would be useful to see it represented as a timeline. So instead of a stored listed, I'd see a cluster of messages in October 2007, and then another bunch in summer 2008, and could zoom in on that.
The closest interface that comes to mind is the bar graph display seen in modern Movable Type admin areas.
Markmail does this for many lists:
If there's a public list that's not archived there, email them and ask them to add it. In my experience, they'll gladly add lists quickly.
I don't think you can get it for your own, private email, though.
