Laptop with serial port

getting a serial port it getting harder and harder, but it more up to chance than anything else. cheap or expensive, doesn't seem to make a difference, just browse around
 
The Panasonic Toughbook CF-53 has one. Maybe others of this sort (outdoor / industrial use) have it. Depending on the serial device you want to connect, you can use a serial-to-usb adapter or a PCMCIA card.
 
Those Toughbooks are awesome, but you pay a pretty penny to run it in a sand filled warzone and drop it 6 feet and still find it working, if all you want is a serial port, though it will give you that it an exception to my "cheap or expensive" comment