It's somewhat doable with the usbnetwork hack, via ssh (or another protocol) over WiFi, (I'd use sshfs on Linux, for example), but it might not be for the faint of heart, and I have no idea how to implement that on non-Linux systems.
On the 'another protocol' front, I guess one could go the overkill way and try to setup a samba server on the Kindle... or Bonjour or whatever the hell Apple uses nowadays.
|