Topsy - Real-time Search for the Social web

The other day I was looking for some ways to index the social activity of someone and I bumped on a search service called Topsy. In their own words, "Topsy is a realtime search engine powered by the Social Web. Unlike traditional web search engines, Topsy indexes and ranks search results based upon the most influential conversations millions of people are having every day about each specific term, topic, page or domain queried".
You can use it to search the web, tweets, photos, videos and experts. This last searchable topic is still in Beta, but it brings some unusual results. Searching for "API" or "Java" would bring a few sites and blogs which are not mainstream, but I could find interesting discussions on some of them.
The "trending" topic search show the most commented topics according to their classification algorithms.

Just a tool to know...