This is just a simple script to make you unfollow everyone you currently follow on Twitter.
To use it, go to the Twitter dev site, create a new application, grant it read and write permissions and fill the script with all the Secret Keys and OAuth tokens.
It unfollows one person at a time and then it sleeps for a second and a half. Just so Twitter doesn't get annoyed.
Also, it quits when the API limit is reached. Just run it again.