As far as I know Android supports Ethernet via USB, right? If yes, since which version of the OS?
What are makes of Ethernet USB adapters which are reportedly work with CyanogenMod? What are makes that don't work so well? Maybe one which are "plug and play" in Windows 7 work better on Android too, compared to those which require a driver?
Edit: As I'm not that technical I'd like to see an explanation, a drawing an article or something of an example of the most easily done USB Ethernet setup on any Android device (esp. the model name of the USB to Ethernet connector is interesting), if it's on stock Android it's even better than if it's on a modded ROM.