Visitors to WP website being able to add their own markers with descriptions/pictures to Google Maps

I cannot describe it in too much detail, and am going to very vague, but this is an idea that my roommate says he would invest in, but the lengthy name for the project is really the gist of it. I want visitors to be able open their smartphones or computers and quickly add a marker to Google Maps that may reveal more information , provided by them, once hovered over or link to another webpage in which they describe an event that had just occurred with words and/or a picture. It would be great if they could just snap a picture with their smartphone and drop it on their location in said map. In either case they'd be anonymous (if they so choose, but their IP's need to be logged to prevent spammers). I am not sure yet how I plan on filtering all of this, but I just need to gather data quickly.