Stop SuperDuper!
 

So I have the unregistered version. Right now superduper is in the process of backing up to a usb hard drive, the data is transferring at .7mb/s. I would really like to stop it but It says that my drive will become unstable. What does that mean? Does that just mean that I will have to reformat the drive?

No -- it doesn't say unstable, it just says it'll be in an unknown state. That just means that we haven't finished the operation, so you'll have a mix of up to date and out of date files, might have your image still mounted (if you're doing an image backup), etc.

Note that your slow copy speed likely means your drive is running at USB 1.x speeds...

I just wanted to make sure it wouldnt make my drive a brick, but I actually asked this question on macworld and some people told me the same thing, thanks for fixing my user name.

A pleasure, atomic16.