Google maps PHP page

I want to have one (or more) SQL tables to hold some data (e.g. name, description, user comments, ratings), location (long, lat) and 0..* pictures. I want a page to display all that data on Google Map, and allow users to comment, rate or propose new locations to be added. I also want users to be able to download the location data in various formats (mostly cvs) in order to allow them to add to their GPS devices. Please have a look in [login to view URL] where users are allowed to download in 20 different formats. Eventually users should be able to login (using their gmail, facebook or site credentials) and suggesting new locations should be based on a CAPTCHA.