Treasure Hunt at Music Hack Day London 2010
Piracy is a really creative android app that lets you drop song tracks anywhere you go, and leave them there like a secret treasure for someone else to find, download and listen to. The fun part is that, in order to get the track, you really have to go to that exact place (plus-minus-200 meters ^_^). Below you can find a test video example about the app:
If you are more interested in this topic, you can find all developed apps at music hack day wiki.