Hey folks
Out of necessity, I happened to make a Torrent Box with a Cubieboard. The same thing can be done with a BBB or a BeagleBoard xM. I described the process in detail here: http://tweakgeek.in/cubieboard-2-as-a-torrent-box/
Should work unchanged on any Debian-based OS (such as Ubuntu). Unlike the Cubieboard, a BBB will require a powered USB hub.