Hi Brian,
Welcome to TechIMO. You didnt state your OS, nor the laptop so I hope this will help (your looking at spending about $200.00 to $460.00) for it though.
http://www.appian.com/products/?page=traveler
Specs:
4 MB of onboard RAM,
Extends the desktop of your laptop across an additional monitor using a Type II PC Card slot, without the need for a docking station
Support for resolutions up to 1280 x 1024
Full plug-and-play compliance
Support for a different resolution on the additional monitor
Was the first one I found(also the cheapest)
Others here:
http://www.shopping.com/xFS?KW=%22pc..._Cards&FD=1722