http://partnersinhr.wordpress.com/2009/09/01/21

One particularly, the Social History of MP3s is really long, but really worthwhile to examine (see audio). … The deal is that as you’re walking through the city, you can view it through your camera and see an overlay of what businesses are in the distance….

The rest is here:
http://partnersinhr.wordpress.com/2009/09/01/21