iptables, a dhcp client and a ssh tunnel and it would make a nice and secure serial to ip bridge allowing access to serial devices remotely over the internet..
It would fairly easy for someone to take one of those devices and create a "serial network adapter" that would allow wired or wireless network access through the serial port, its not going to be nearly as fast but it will be freeing up the cf..
another idea, might be kinda cool would to make your zaurus sync cradle a standalone network appliance, this could allow you to sync your data across multiple machines, say when I plug my zaurus in the cradle it syncs with my home pc, my remote workstation at work and my laptop on wifi, or if it could run a webserver you could manage your zaurus with a web interface which could allow syncing a pda across multiple platforms plug and play or more user friendly.
I could think of several dozen good uses not related to a zaurus tho, accessing any type of serial device over a wired or wireless network could come in handy for lots of things. Could have some intresting covert uses such as backdoors into systems, industrial espinage, etc..
