Another interesting piece on the housing bubble. I know it's dated but a great piece on how the housing bubble grew to it's enormous proportion. It provides a great example how the machinations of Wall Street weren't necessarily orchestrated. Rather certain events, such as a creation of a formula, could be used misinterpreted to disastrous consequences:
Recipe for Disaster: The Formula that killed Wall Street.
http://www.wired.com/techbiz/it/magazine/17-03/wp_quant?currentPage=all