I have a backup drive -- in fact now I have three external drives, 300Gb, 700Gb and now 1TB. The 300GB drive is full of comic scans -- only. The 700 GD drive had everything it did, plus more stuff like comic strip scans. It also was where I put my working files becuase they're too large for my hard drive. There was no more space on the smaller drive to back those up.
Now I should be set -- of course I thought that a year & a half ago when I bought teh 700Gb drive. stuff expands to fill all available space it seems.
Jon