I've run into the same problem as you. The screen is going out on my old laptop so I had to buy a new one. When reviewing laptops online, I could've sworn that the new one I got had a serial port. But last night, I was plugging in my USB floppy drive and noticed that it did not in fact have a serial port.
This evening I purchased a USB to serial cable at Radio Shack for $39.00. I'm going to test it out tomorrow and see how it goes.
The documentation that came with the cable states that it fully supports RS-232 for modems, PDAs, cameras and label printers, etc. so I'm hoping all goes well.
If I'm successful, I'll let you know.