Just been watching a History Channel documentary on 2012 which is pretty respectful about the prophecies. Here is a short list of the sources they refer to which predict the "End Time"
Mayan Calander
I Ching
Oracle Adelphi
Merlin
Mother Shipton
Revelations - Bible
Black Elk - Sioux Prophecy
Hopi Prophecies
"The WebBot Project"
The Mayan Calender and the I Ching both predict the date as 21 December 2012. The others describe the same things of seas rising and sky falling. The Webbot program was something that was set up on the internet in 2000 to try and predict rises and falls in stocks and shares by scanning for different keywords used. In June 2001, someone searching thorugh the results got a chilling feeling that something would happen in the following 90 days that would forever change life in the USA. Then 9/11 happened. So they then used it to make certain prediction about the next few years which came true. Things continue spiralling down for 2012. The Hopi prophecy is the only one they described as not talking about the end but the beginning of a fifth age.