Sweet I just found an answer to the multiple serial port problem- with the added benefit of giving the Empeg wireless ethernet. My plan is to use a WRT54G hacked with a linux kernel and then use instructions on this page to add two serial ports (except I'll use a different TTL-RS232 adaptor). Then I could run GPSD on the WRT54G and leave the empeg's serial port for my OBD-II reader (which I'm still trying to get to work on linux). Cheapest solution I could find so far for getting an embedded linux box to run GPSD with, unless someone has a cheaper idea.