What do you do if you've got a laptop and need RS232 serial? This is a high quality, low cost, small, and easy to use USB to RS232 converter. Device uses the Prolific IC PL-2303 and supports baud rates up to 1Mbps. Driver support for Windows, Mac, and Linux RedHat.
This converter plugs directly into your USB port on your computer and even comes with a small extension cable and CD for drivers.
Alternate drivers can be found on these pages. Vista 64bit may be a problem for some people: