CloneSpy is a great tool for cleaning up your harddrive by finding duplicate files and removing them. It looks at size, names, and even approximate names/size. It also gets rid of zero byte files if you so choose. You also have a choice of not removing the files, but moving them to another directory. This allows you to restore anything you might have accidentally deleted.
Would there be a reason not to use CloneSpy? Well… just don’t run it on your full computer if you map a backup drive. Since there would be plenty of false positives then, wouldn’t there.
Lifehacker < Clonespy