Finally, someone has figured out a way to use the USB connection on an Apple TV to connect to an external hard drive. This is good news for folks wanting to greatly increase their download capacity.
The hack is not for beginners, and requires an Intel-Mac or Intel-based *nix to run the script.
For information and tutorial help on making use of this new hack without needing your own Mac expert, see the details here: Apple TV Hack
Check out this article on hacking Apple TV to enable the SSH.