Basically for this project I stick some disposable cameras around.
Got the idea from a few online bloggers!
http://theplug.net/28/strangerphotos.htm
http://www.glamour.com/sex-love-life/blogs/smitten/2009/02/we-left-two-cameras-on-new-yor.html
http://www.flickr.com/photos/richard_pigg/sets/72157608216732457/detail/
http://www.flickr.com/search/?w=all&q=disposable+camera+on+bench&m=text
http://www.runnysnot.com/hangingcamera/