Here is a very interesting recent clip from the Colbert Report based on Prothero’s recent book entitled God is Not One, the point of which is that those who say all religions are one (and therefore bad, or therefore good, or are all different paths up the same eternal mountain, are simply wrong). The book focuses on the eight most well known religions.
http://www.colbertnation.com/full-episodes/mon-june-14-2010-stephen-prothero
(Skip to the third marker on the show)
http://www.comedycentral.com/colbertreport/full-episodes/index.jhtml?episodeId=312495