I have only recently stumbled across the Mayan 2012 cataclysm belief, which I gather is very popular in some quarters. For those as yet unexposed to this wonder, it concerns the fact that the Mayan "long count" calendar (they were fond of grouping years into various different cycles) comes to an end on 21 December 2012, when some terrible event is predicted to happen. It is also claimed by one Terence McKenna, who invented something called "Timewave Zero" which "purports to calculate the ebb and flow of novelty in the universe as an inherent quality of time", that "the novelty [is] progressing towards the infinity on 21st December 2012". (see THIS item). Wow! With modern mathematical theory backing up ancient Mayan beliefs, there must really be something in this, right?
Just a couple of problems with this: the Mayans did not predict catastrophe at the end of the long count – in fact, they had celebrations at the end of their year cycles to welcome in the next cycle, just as we did at the end of the Millennium. The predictions of doom were the recent invention of a New Age theorist, José Argüelles, whose ideas have been dismissed by all professional Mayan scholars. As for McKenna, it turns out that no serious mathematician has accepted his ideas: they are just numerology (which is in the same category of scientific validity as astrology). Even more damning, McKenna (an advocate of "magic mushrooms" as the key to understanding), deliberately changed his initial calculations to match up his critical date with the end of the Mayan long count, so it is hardly surprising that they are the same.
As one contributor pointed out in a discussion on 2012, we needn't worry about it even if you believe such catastrophe theories because we're not going to last that long. The end of the world is supposed to happen in 2010 according to the Hermetic Order of the Golden Dawn, or 31st December 2011 (if we fail to rid ourselves of all evil) according to Solara Antara Amaa-ra, leader of the "11:11 Doorway Movement". The fact that countless "end of the world" predictions have come and gone doesn't seem to discourage such fantasists. I suppose it could be regarded as the triumph of pessimism over experience!