Simply enter your twitter name and they analyze your 200 latest updates and flag those up that made people follow or leave you.

Of course there are more factors that make people come or go, but it is an interesting indicator about the effect your tweet might have had on the world.

TweetEffect is a test – you could call it a hack to try out some of the Twitter API functionality mixed with free Yahoo and Google services. Maybe this will go places, maybe it won’t.

Check it out at http://tweeteffect.com/