Hi there,
I hadnt seen slip since about 1992.. yes it works like a charm hooked up to debian 5.0(under vmware fusion/OSX).
hmm I am currently looking at wrappering the telnetd/shell example to arduino and replacing the shell with bitlash(www.bitlash.net) and running the result on either sanguino(644P) or arduino Mega 1280P.
Still looking at uip sources at this point and talking to the author of bitlash about possible attachment points/glue code.
gwen