In July the Google Maps API for Flash introduced the Map3D object which allowed developers to present a 3D view within Google Maps mashups. Surprisingly I haven't seen many maps that have used the new 3D perspective. StreetSounds is the first mashup I have seen for while that has used the Map3D object and to do so to such good effect.
The StreetSounds map is an interactive tool for sharing and listening to sounds from all across the United States. The map allows users to upload sounds and discover sounds you have never heard before. Using the map you can listen to the sound of places you've not visited or relive memories from those you have. The sounds range from a Berkeley student demonstration and a bustling intersection to an arguing couple and a band rehearsing.
As well as the StreetSounds map a competition is also set to be launced, challenging film makers to create films based on the sonic landscapes of cities. The films must use at least three sounds from the Sound Map and be 3:00 min or less in length.