http://www.thetwittertools.com/tweets/
Can people still automatically based on Twitter tweets?
When my friend mentioned something about a twitter antifarmville began Farmville to follow her, when I said something about a Twilight Twilight Fanclub started following me and spent about a minute after I posted the tweet. I was wondering if it was possible that people automatically follow based on what you say in your tweets?
Yes absolutely there are many software scripts out there, one of them is called Hummingbird where you enter keywords and then start following people automatically. However, this can cause a lot of people do not like you to follow and then block you, and the results of the account may be banned.
The Birdie Song – The Tweets