Google Follow Finder works this way “Follow Finder analyzes public social graph information (following and follower lists) on Twitter to find people you might want to follow.” Simply put Google will analyze and suggest people for you to follow on Twitter and it does help if you have been using Twitter for a while.
To begin with visit http://www.followfinder.googlelabs.com/, and enter your Twitter username/handle and hit search. Google will then suggest people you should follow, of course based on your past Twitter usage. I must admit the first couple of pages thrown up by Google Follow Finder were pretty accurate and indicative of the kind of people I would want to follow. Give it a try, I’m sure you will find a few interesting people to follow like me for instance. Even otherwise you can follow me at http://twitter.com/moserw.