Using the "Menu Extension" in the "Settings" part of the menu, you can try the "USB Host" section.
Try turning on the "USB Host" then turn on the "Storage" one as well.
I'm told that for most people that will pick up and external USB hard drive and mount it under the "ext" option on the menu.
I've had to use BASH script to get the drive mounted but I think that was more to do with the HD I was using. I can dig the script out if the above doesn't work for you.
Hope that helps!
Edit: grammer and missing words!