What do you mean more useful? Whats the difference?
iPod have an option entitled "Enable Disc Mode", or something im running from memory here.
When its enabled, your iPod will appear to any computer it is connected to as
just another external hard drive, so you can read and write to it independantly of your iTunes music, videos, settings etc.
Which means you can use your iPod on any Mac, any PC (be that Windows or Linux) or something more exotic and rare such as Solaris or Amiga OS.
Did you know that peter Jackson used his iPod to transfer rough unedited, footage of the Rings Trilogy from his studio to his home for exec's to watch?
80GB is a good size for an external unpowered USB hard drive you know.