Came across Twitterank today. It is "Google PageRank" for your Twitter Profile. It has a secret algorithm that uses many signals, not including your follower count. Looks to be some sort of index, because I have seen some scores above 100. My current Twitterank is 97.99
READ: Just an update on this tool. It came out that this site was thought to be a phishing scam for your Twitter login information. You can read more about it here and here. This just brings more attention on how these Twitter apps/programs can be used maliciously. One tip I read was to change your password temporarily when using such services and then afterwards change it back to your original password.