Hey, better prepared that sorry!
http://www.2012store.net/
Now you know where that 200 year-old Salsbury steak in FO3 comes from...
Do you know what happens after the end of the 13th Baktun? The 14th Baktun starts on kin 1.
The 13th baktun ends on Dec 21st, 2012 just as the 20th Century ended Dec 31st, 1999 (or Dec 31st, 2000, whichever your point of view)
The baktun is simply the highest cycle in the Mayan calendar.
Just like we have day-week-month-year-decade-century, the Mayans have kin-uinal-tun-katun-baktun
(ok, so I was born In Yucatan, Mexico and I am showing off, sue me
)
And the Mayas never predicted anything close to the end of the world. There actually are Mayan steles that mention dates in the 40th century. This whole thing started mid-80's with some bogus astronomy by the usual doomsday-prophet types.