AirBnB's first acquisition? Seriously though, this is my new list of San Francisco date ideas: <a href="http://www.vayable.com/bay_area" rel="nofollow">http://www.vayable.com/bay_area</a>
I was discussing the exact same idea with a friend a few days ago. We kind of started working on it, but got bored so didn't follow through. I'd definitely use something like this.