A good GPS can take the stress out of a roadtrip, keeping you on track and helping you find places to eat, sleep and fuel up along the way. The portable GPS market has virtually exploded in the last year or two which means that shopping for a GPS device can be quite an overwhelming experience. And GPS devices do more than navigate now--they play music, display photos and even serve as a handsfree speakerphone. Not to worry though, we're here to help you find the right one for your needs. Hop over to PCMag.com for our full guide to buying a GPS device. We explain the technology and feature-sets and share some of our favorite devices.

This story was pubbed just days ago, and already TomTom has released yet another compelling, not to mention free, feature: Map Share. Available on the company's newest devices, the GO 520 and the GO 720, this function adds a practical social networking/Web 2.0 tool to GPS navigation. Anyone who has used GPS or an online mapping service such as MapQuest knows that their directions are not always 100 percent accurate. Roads change--they close, they open, they get renamed, rerouted, you name it. With Map Share, TomTom users can add their own updates such as "unblock street," "reverse traffic direction," and "edit street name." Sometimes a street may be missing altogether, and you can report that to TomTom as well.

Points of Interest (POIs) frequently change too--new ones pop up every day, old ones close, phone numbers and addresses change. Drivers can add, remove or rename a POI, and edit its contact information too. While this functionality sounds useful, it could also turn into a mess with so many editors. So when you sign up for this service you can choose to receive only your changes, changes verified by TomTom, changes from trusted sources and more.

This is definitely a new direction for the GPS market, and one we expect to grow rapidly. With the wealth of local knowledge out there, the options are endless: after all who knows better than a local all the best shortcuts and the easiest ways to circumvent traffic.