Mapquest Navigator. Coming soon to a mobile phone near you. Voice guided, turn by turn directions. How they gonna do the GPS thing then? More info needed, boys.
MapQuest Navigator uses the latest technology to turn your phone into a full GPS Navigation system. Decide where you want to go and MapQuest Navigator will help you find it and guide you there quickly and easily, anywhere, anytime! MapQuest Navigator provides you with voice-guided, turn-by-turn directions to a location either from a selected starting point or from your current location, using GPS technology. Routes can be optimized for speed or distance when driving, or for pedestrian routes when you’re traveling by foot.
Most new American mobile phones come with “location-based services” (LBS) due to the E911 regulation (which requires the phone to report it location when an emergency call is made). Sometimes it uses GPS, sometimes it’s tower triangulation – it depends on the carrier. Google E911 if you want more info. There’s also stuff on the Sun website about accessing LBS through the Location API using J2ME, for the mobile developers out there.