world map news

im looking to start a website based on php and html5 so anyone can view it on their mobile and computers especially iphones, ipads, etc...i want a page simply start with a world map and singup section for new users or already registerd users to log in. once registered they will have to choose from a map interface their region and than their country than thier city. after that they will be able to post their videos or pictures and have something to comment about it like youtube i want them to be able to upload pictures and videos and comment on any of them and share them on diff sites like facebook and so on.