Alleys in Chicago…wow!

I am fascinated by these great alleys in CXhigago and am looking for a guide or a forum.

Here are some articles a a huge video that I will place on davehensleigh.tumblr

http://members.tripod.com/chicagotheroarin20s/alley.html

http://www.encyclopedia.chicagohistory.org/pages/38.html

http://www.nytimes.com/2007/11/26/us/26chicago.html?n=Top/Reference/Times%20Topics/Subjects/C/Conservation%20of%20Resources

http://newurbanist.blogspot.com/2005/11/exploring-chicagos-alleys.html

video:http://www.youtube.com/watch?v=rBOH91h_Rfw