http://impromptudo.com is a small project I've been working on. Just a webapp for now but I think it qualifies as an MVP. Also has a mobile version at the same url or http://m.impromptudo.com. Right now it pulls in data from meetup.com for upcoming meetups in several populous cities so it's not just an empty map. You can also click on the map to put up your own post. Trying to stay away from making it all social networky, there are plenty of those already.<p>Finally, I'm not a designer, as you can see.