Tweetake.com is my favorite. I use it for both of my twitter accounts:
twitter.com/drsallywitt
twitter.com/sallywitt
It is easy to use, and designed by two friends that I know from Ecademy: Alfred Armstrong and Nikki Pilkington.
Try it, wouldn't you be sad to lose your followers?? It only takes a few moments. Be safe!
Dr. Sally Witt Social Media/Networking Coach & Trainer