Avoiding traffic jams is top on every commuters list this year. Real time traffic information often requires an extra device to receive the data sent on FM, cellular, or satellite signals. You'll also often have to pay a monthly, annual, or lifetime fee. MSN Direct, bundled with some units like the Garmin nuvi 680 is available for 120 cities and not only gives you traffic info but adds gas prices, weather, and movie times. Some GPS devices like the Navigon 7100 include free lifetime traffic.

Text-to-speech (TTS) lets the GPS device give you audible street names, directions, and points of interest (POI) information. This feature is sometimes called spoken street names and is pretty standard in most high-end devices. The Navigon 2100 is a new low price GPS device that offers TTS.