This is a JLC article on new roofing strategies that cut down the cooling load in climates where most of your energy bills are for the AC. Note this is a PDF file and may take a few moments to open.
http://www.jlconline.com/cgi-local/viewnew.pdf/0/69e1b8a218d0f9a509ff834b3f15583e/www.jlconline.com/cgi-bin/jlconline.storefront/4c224c070e98272827170a32100a05a4
Here is the overview of the article and an html version if needed: http://www.jlconline.com/cgi-bin/jlconline.storefront/EN/Product/0306cool