I wanted to experiment with a USB 2.0 network adapter for my Cr-48 and went ahead and picked up the following:
D-Link DUB-E100 USB 2.0 Fast Ethernet Adapter
The Cr-48 detected it right away:
[ 123.288513] eth0: register 'asix' at usb-0000:00:1d.7-6, ASIX AX88772 USB 2.0 Ethernet
I won't get a chance to experiment with it more until Monday, but just wanted to throw out another potential wired ethernet adapter for those out there in the same predicament (crappy wi-fi outside of my control).
At 100Mb, you could do 12.5MBytes/sec max over USB 2 - so I'm not worried about the network being the bottleneck on the Cr-48.