"Social Search" is like "Web 2.0" in that if you ask five people what it means you'll get back seven different definitions. To me, the user experience for 'Social Search' is pretty straightforward. I'd like to ask questions and get back answers that take advantage of the knowledge the application has about my social circle (e.g. friends, family, trusted experts, etc).
The incident that got me interested in social search happened two years ago. The apartment complex I lived in [Avalon Belltown -- don't stay here, my car got broken into in their "secure" parking deck and they acted like it was my fault] raised my rent by $300 when my lease was up. I thought that was fairly obnoxious but didn't have the time to do an exhaustive survey of apartment complexes in the Seattle area to find one that met my desires. I knew that one or more of my co-workers or friends would be able to give me a suggestion for a cheaper apartment complex that would meet my requirements but short of spamming a bunch of people at work, I didn't have a good way to get this information out of my social circle. So I stayed there after renegotiating the lease [which they later reneged on but that is another story].
Since then I've been interested in the notion of 'social search' and other ways to make the user experience on the Web better by taking advantage of the knowledge applications have about our relationships to other people. This is why I ended up working on the team that I work on today and have been involved in building features such as Social Networking for Windows Live. I believe that we are now about halfway to what I'd like to see in the 'social search' arena at Windows Live. We have Windows Live QnA, Windows Live Expo, and Windows Live Spaces which I see as different pieces of the puzzle.
The next step for me has been thinking about how to extend this notion of applications being smarter because they know about our relationships outside Windows Live by exposing APIs to the different kind of relationship information we have today. This is one of the reasons I find the Facebook API quite fascinating. However I'm not sure what the right forum is to get feedback on what kinds of APIs people would like to see from us. Maybe asking here in my blog will get some bites. :)