Not seemlingly elluding to Mr. JackMDS point, I say you go with linux on this one. 
1 
Putting linux on a thumbdrive is doable but make it small (gentoo, debian..whatever....)..this assumes a lot about the host PC mind you.
.2 
make it automatically check for hardware 
(add every netowrk module you can find to the kernal...hello slow bootups

 )
.3 
make it automatically configure these with a static IP address
.4
assume that it will connected with a crossover cable to a switch. 
5.
Have it automatically bring up a dhcp server on that link if it can bring it up...
What devious plot do you have hooked up boi?! :evil:
Oh, and I only gurarentee that the 1 will work...all the decimals are useless.
