Wow - sorry I am late to the party.
YES - ABSOLUTELY you can plug a USB HDD into the 3808 and listen to your stuff.
Some things to think about:
1) The 3808 has a front and a rear USB port. If you are plugged into one, the other won't work. (Don't get me started).
2)This approach kind of limits things for you. If you can plug the HDD into something else (Wii, PS3, DirecTv receiver, Xbox 360)and then into the Denon, other fun stuff opens up (video, pics, streaming your music, etc.)
3) The 3808 is set up to be a wired connection but given the way I am scattered throughout the house, that wasn't going to work. I set up a Linksys WRT-54GL as a wireless router (2nd floor of house, upgraded antennae) and added a WET54G wireless bridge in the basement home theater. I plugged the 3808 into the bridge and it was very happy - it had a plug and therefore, though it was a wired connection. Also plugged a powered 8-port USB hub into the PS3 and plugged a 750GB & 320 GB HDD to the hub. RESULT - everything everywhere.
Answer may be overkill, but the HDD into Denon will work.
Ray
