The last couple months have been interesting for me, one of the big evolutions has been Timelope. A new project for helping people share their browsing history. This sounds like an odd proposition, and maybe it really is. I certainly didn't think much of it until I really started playing with it and the ideas started pouring out.
Basically the pain point is that accessing your browser history is not particularly fun or engaging right now (Firefox 3's awesome bar goes a long way to solving this), but beyond that acting as a medium for discoverable browsing. Reddit, Digg and Delicious all do some form of this. They might sell themselves as social news or social bookmarking but their big traffic comes from people looking to discover new sites, or find information they would find interesting. The problem with all of these sites is that it requires explicit action on the part of the user to submit new material, which means they're reducing the size of their data pool significantly and self selecting a portion of the people in their community willing to submit new material.
So I've been working on the Firefox extension for Timelope which has been a lot of fun. And by fun I mean painful, but at least a new kind of pain. I have way to much to say so I'll say more later.