What would be the best way to go about this?

So I’m helping a friend build a site, and he says he’d like to see if there’s an option to show people a map, let them place marks on it, and then let them post a short blurb about that placemark. Long story short, he just wants an open map for people to edit and markup, but the emphasis is on the little blurb that the person can do, sort of like a blog entry.

Is there any way to do this via Google Maps/Google Earth, Mapquest, or another 3rd party service, or would I have to write code for it?