Nice presentation (9 min.) by Luis Suarez to whom I've been pointing regularly on my blog. This is his presentation at the Web 2.0 Expo in Berlin (added in below). It gives a good overview of how he's trying to stop using e-mail for the wrong reasons and what he experiences doing this.
I've asked the question before, but I'd really like to hear more from Luis about the time he used to spend on email and the time he now spends on email and the social tools. (Something for the Sweettt podcast, Luis?!)