Mozilla has announced an interesting project called Raindrop, which appears massively complicated on the surface but is actually quite a simple idea when you strip it free of buzzwords.
Mozilla (like Google, with its Wave platform) says that "email isn't fun any more". Instead, conversations are taking place all across the Web - in IM, Twitter, blog comment threads, Facebook, and other locations. Raindrop wants to aggregate all that in one place, and sort it so that the useful stuff comes straight to you.
Unimportant messages, like mailing lists, will be relegated to the background whereas the email from your mother telling you she's booked a family holiday to Barbados or the IM conversation from your girlfriend telling you that she's pregnant pops up front and central.
At the moment the project is at version 0.1, so it's only open to developers. You won't be able to download a client just yet, and the team's first task is to create an installer for the application. Still, it sounds like an interesting idea, and we'll keep an eye on it and we'll let you know when it's available to try.