Incidentally, an old Palm Pilot would make an excellent platform for
this sort
of thing. They're thoroughly well understood; powerful OS kernels that
will
run on them are freely available (ucLinux); they've got decent I/O
capabilities and expandability. I'm sure I could come up with a use
for a
robust device that ran for a week off batteries, talked TCP/IP over
IRDA, had
a graphical display, could control other devices via a standard serial
interface and was trivially scriptable in Lua...
They're also cheap, which helps.
