Garmin's GPS 18x "puck" type sensor connects to your laptop via USB and is a "plug-n-play" option for those seeking to add GPS capability. The GPS 18x is rated as highly accurate, and is WAAS-enabled. It comes with an integrated magnetic base, and is less than three inches in diameter.
Modern laptop GPS devices have been stripped down to the basics: In this case, the USGlobalSat BU-353 provides terrific GPS service at a budget price. The BU-353 has a SIRF Star III GPS chipset, is WAAS-enabled for accuracy, and is waterproof as well. The compact USGlobalSat GPS receiver plugs into your laptop's USB port.
DeLorme – a company that made its name in paper maps but has moved into digital in a big way – offers a laptop-compatible GPS receiver and accompanying Street Atlas USA mapping software.
DeLorme has made major improvements in its new receiver and software. The Earthmate GPS LT-40 (plugs into laptop via USB cable) features a high-sensitivity WAAS-enabled GPS receiver, and the Street Atlas USA software has an abundance of upgraded and updated information, and a sharp new interface. Highlights of the interface (shown in photo) include a "cockpit view" of airplane-inspired navigation cues, and a wide, 3D perspective of your route. This edition also features an E-Z Nav Wizard, and navigate-from-search results.