[NCLUG] multiple-serial port laptop?

[S. Luke Jones]

I'm trying to figure out how to demonstrate serial device
connectivity (for e.g. a trade show) using two laptops. One
I can spec and will run Linux, the other would have to be
whatever the sales droid normally uses (a windows box with
probably a single serial port (if that)).

What I'd like to do is have two separate serial connections
between the sales guy's PC and the Linux PC. I'm pretty much
stumped how to do this, given that there's only one port on
one side. (Possibly both sides: all the laptops I've seen
in the past, oh, 5 years have at most a single serial port.)

So can anyone suggest alternatives? Hardware or software?
Could I use the parallel port? Could I get some kind of
ethernet to serial gateway (small enough for the sales guy
to pack around with him)?

Thanks,
Luke