Hey, check this out. Instead of hooking up a PC, how about a laptop?
Maxtor QuickView QVX Expander- Upgrade your Scientific Atlanta Explorer 8300 HD, 8300 MR and 8300 HD-MR
I am totally with you. I asked my cable company if it could interface with an external HD, and they said, "sure"... Am trying to get to the bottom of this now. Any further luck in your search?