Originally Posted by ixtab
That's probably even more difficult than what the OP asked for. For your setup, you'd need loads of additional hardware, as well as OTG support on the Kindle *and* the correct driver for the LAN adapter. That's a lot of question marks and work, if it's feasible at all.
Just put a WiFi hotspot somewhere in a corner, set it up with WPA2-PSK (or even better, Enterprise WPA2), and configure it to only allow the Kindle's MAC address. Reasonably safe, zero maintenance after setting it up, and no hassle with the Kindle either. And you can even walk around with the Kindle
If he must abide by a "no wireless" rule, then USBnet is currently the only way to go. Otherwise you need to find a USB LAN adapter that has ARM linux support with a loadable kernel module compatible with the kindle linux kernel (or a custom linux kernel). USBnet is a LOT easier, and already works.