GPS sensor will exactly cost you an arm and a leg these days, but monies is monies, and Navizon's new "software only GPS" solution sounds like it'll do the trick just fine. It's not an exactly new idea, but Navizon is really bringing GPS to the peoples with their "peer-to-peer" solution that uses WiFi base stations, cell towers and actual GPS users to triangulate location data for users. The Navizon API can now be embedded straight onto a webpage, giving web developers new nefarious ways to track users, or perhaps even offer fancy functionality if they're feeling particularly magnanimous. There's also a mobile API, and a "reward program" for devices that are packing their own GPS functionality and contributing location data to the system. Sounds like a good time for all, but we'll be interested to see how this works out in practice.