With TwtMate you can find new people based on your interests.
And the best thing about TwtMate is that it is 100% free!
Step One: Enter your Twitter Username and Password and you will be logged into your twitter account through Twitter Match
Step Two: Enter your interests
Step Three: TwtMate searches the Twittersphere and hand picks users to follow based on yours and their interests alike!
Easy as 1..2..3!