Collaborative Map

We're trying to construct a collaborative mapping tool for our wordpress-based website/blog.? ? What? we'd like is an interface by which site visitors could contribute to a mashup without first being redirected to a separate, external google map page. ? Ideally, there would be a couple of fields for visitors to fill (i.e. listing name, address, brief description with links). ? Also, they'd be able to select a map icon appropriate to their listing. ? Ultimately, we'd like to link user-identified locations to relevant media of various forms, if not embed media into the map.? ? In order to keep things manageable, there has to be some editorial control over what gets listed, ideally linked through the system we already use to manage content.