Graph Search is the new social search engine from Facebook meant to help you connect with people of like interest, find all the photos you have liked, find friends in a particular area, you get the idea. It sounds cool. You could ask it something like "What lunch do I want" and it would peice together ideas based on your friends likes and dislikes. In other words, it's time to lock down your profile now.

If you are not concerned with that level of knowledge about you on the net and would like to be on the waiting list for the beta go here: https://www.facebook.com/about/graphsearch