I like it a lot. A couple of critiques: - I had to look for what the app was. Yeah, the explanation is on the right, at the top of the sidebar, but I'd almost like to see it above the google map on the page. - I'm not terribly keen on the font choices throughout the page... specifically what's bothering me is the character spacing, most noticeable on the right sidebar.

On the whole, I think it's a brilliant idea, and at least to my knowledge, isn't being repeated anywhere else. That said, I'd focus on layout and design, and accentuate the social aspects of the site where I could.