Tracks on a Map
This Google Map shows the locations of bands that have uploaded tracks to SoundCloud and even lets you listen to the tracks directly from the map.
The tracks can be selected by genre of music. Selecting to view markers by genre gives an interesting view of which types of music are popular in different parts of the world at the moment.
Clicking on a map marker opens an information window which lists the tracks loaded from that location. Clicking on 'play' lets you listen to the selected track. I'm currently listening to the Superfantastics out of Brighton, although something tells me this isn't actually where they are from.