[miguelpais]

Once I thought of something like that too, but in the environment of a park with speakers and wifi (yeah, far fetched, I know). People could go to a website available on the wireless network with their smartphones and pick a track to play (from a library such as Spotify). Then everybody on the park would be able to up or down the track using their smartphones. If the track had enough up votes, that person would be able to pick another track to play.

It would be the interactive/social/sound park. :P

But since I don't know that many parks with speakers, on clubs it would probably work better. They could do it as an experiment on a tent of some festival like they did with the concept of the silent disco (http://en.wikipedia.org/wiki/Silent_disco).