Topsy is a very promising start up company that provides a search engine to search for social media trends across the web in real time. This can be critical for businesses who wants to find out about trends that can help your business, personal users can use it to search for your favorite topics and even see what's trending now on the web.  Topsy pulls resources from all over the web so it's not just twitter and facebook. 

What we like about Topsy is users can search by tweets, images, videos, and even experts by topics, really an awesome tool