A version of Navizon Virtual GPS is now available for the iPhone.
For those of you who are not familiar with this stuff, Navizon is a positioning system that triangulates signals from Wifi access points and Cellular towers. It is based on a collaborative database where users who have a GPS device can contribute data on Cell towers and Wifi APs locations that will let other members of the community simulate a Virtual GPS on their phone.
The best way to install Navizon is through Installer.app (if you have it installed on your iPhone already). You can also download the zip file directly.
This application will be fully functional for 15 days. If you like it, you can purchase it for $24.99. But for those of you who of you who may wonder what this money is used for, it isn't going in the authors pocket. It is used to pay the ones who do the hard work of collecting the data without whom this service wouldn't be possible.
PDRoms Note: This software isn't exactly 100% free, but as the author doesnt make money from it and the money is used to improve the given service, it made it on the main page.