We just released a new version of Navizon GPS called Navizon Lite. This version is totally free and will let users get their position using the surrounding cell towers.
This new service is similar to the one that Google launched last weeks with its "My location" feature (approximately 1000 meters accuracy) only that it works on the iPhone.
For users who need a more professional accuracy, they can upgrade to the full version (free to try, $24.99 one-time fee to buy) that combines WiFi and Cellular positioning, offering an accuracy of approximately 10 to 30 meters in an urban setting.
Both versions will let you get your directions to your next destination and see where your friends are located on a map with the Buddy Finder.
More
details on this new version are available on the Navizon
blog.