Bulk Unfollow Twitter Users with ManageTwitter
ManageTwitter is a website which allows you to filter and bulk unfollow twitter users so you can cleanup your following list.
unfollow tools
Bulk Unfollow Twitter Users with JustUnfollow
I have been looking for a decent replacement for huitter mutuality and the creator of JustUnfollow had me look at their site. It is useful and simple to use.