OK well I've moved into producing 30-minute vidoes for YouTube and my 1TB hard drive is filling up fast. I have the original movie files, a copy of them within iMovie, and then the exported MOV file ready to be uploaded to YT. So, the thing is I'm running out of space and want to add an external drive just for all the movie stuff. I'd like to know if there is an external drive that somehow hooks onto the iMac on the back using a shelf or something? And if so, could it be backed up using Time Machine? The HD on my Time Capsule is 2TB so I should be good there for a while yet. **Ideally I want an external drive that doesn't sit on my desk** I just want to make sure when it's all said and done that I have the movie files physically located on two different drives (one local, plus the time capsule).