Changes to a PHP location based site

I have an already implemented and running web site for location tracking, running on Linux, Apache, PHP and postgresql. The site is 100% functional, but the map service I'm currently using (Webraska) is paid. This project is all about replacing Webraska by a free alternative (Google Maps perhaps?). ## Deliverables I understand that the description is somehow vague, but we can understand each other during the implementation, as I'm a coder as well. Understand also that this is the first of many improvements I'd like to do to this service, and the winning bidder will be invited for the next steps.