I wrote about Social Search last year, blogspace has had it for a while in a form of searching what your friends have found (e.g. my.feedster). John Battelle, who is blogging the expanding space of search covered it a month ago. Eurekster launched its social network constrained search service today. That said, its is pretty cool. Sometimes sharing what you are looking for can help you find it and more. The search itself leaves a little to be desired, as its no Google and doesn't benefit from micro-content structure. Browsing the search terms of your friends (like this) is similar to looking at them in your referral log. Get ready for a different kind of social spam as people can ping you if they browsed in the same direction as you. It begs the is it a feature question, but anyway, the beta is out, tinker away.