USB External HD

Hi all, I'm new here so please forgive me if this question has been asked and/or debated. (I did search for it and found several posts put most dealt with other issues)

Is there a way to hook up a USB external HD to a Tivo to gain HD space?

I know all about hacking and adding new HD to these units and I would like to avoid all that if possible. It seems to me that Tivo put the usb ports there for a reason, and hooking my Tivo to my home network is one thing but that can't be the only reason they are there. Plus someone else out in the world must have thought about this and I have seen some pretty amazing things people have done in the past. Once all of the channels go High Def it would be totally awesome to have this option available in the future.

If anyone from Tivo reads this you should really look into this for people like me that have units that they are happy with but are unhappy with the recording capacity in High Def. Maybe Tivo could introduce there own external HD to add disk space. What would it hurt?