Yes, you can, and it works quite efficiently.
Before we dive into burning them and such, lets get XBMC as your dash. Get the AID iso from here:
www.aidtracker.com
Once its finished downloading, pop it into your Xbox, and choose XBMC as the Dash choice.
Now, once that is done, burn what you want to a disk (movies, games, whatever)
Load up XBMC, and navigate to the tab labeled "System", and then go to Memory, and then File Explorer. After that, go to the D: Drive. Now you have to press the right arrow on the D Pad, then navigate to where you want whatever files it is to be stored. After you're in the folder, press the left arrow on the D Pad, and highlight whatever item you want, and hit the white button. Now just press copy.
Hope that was simple enough.
XBMC supports many different media types, I haven't even tried all of them yet.
A USB memory card is very handy, I use mine so I can hook up a keyboard when I use Linksbox, works nice.
Anyways, if you have any other questions, let me know.
