Another thing to consider is the Mayan Calendar. The date of 12/21/2012 held special significance for them. . . .something along the lines of the world coming to an end due to a rare celestial alignment. Part of the alignment is the Earth arriving at the end of one of its axial rotations, something that happens on a timescale of tens of thousands of years, I just can't remember exactly. There are other factors in the alignment, as well, but I can't recall the details. I saw this on the Discovery channel (or a similar one) just a few days ago.