I heard all this on an ancient history class about the Epic of Gilgamesh, back in 1998. Back then i was like WTF!!!
I couldn't stop thinking for days about what the young professor told us.
He started with a comparison between Noah and Utnapishtim and then he told us the same thing the guys from Zeitgeist tell about Jesus and Christianity.
The thing is that every historian who specialized in ancient history will confirm that what they say is true. Every medievalist will confirm it's true. The astrologists will probably confirm it also. Everyone who studied the history of religion will completely agree with what they say.
Everything is crystal clear actually.
In case someone still didn't see tha part about religion, it can be seen here:
http://www.youtube.com/watch?v=KeZB2EsPqGE&feature=related
http://www.youtube.com/watch?v=XmzailhVl-U&feature=related
http://www.youtube.com/watch?v=m6UdQxt7b24&feature=related