There has been a way to root the Samsung Fascinate phone since launch, but only for PC. If you are on a PC and you don't have the instructions already, you can follow them here. All you have to do is download the zip file and download the instructions.
But what do you do if you are on a Mac? Well, now you have easy to follow isntructions on how to root Fascinate on a Mac, too, and they are even on video so the rooting process should be painless for you: