Over the last few years I've been studying what the Mayan Calendar is really about. It's quite a positive thing actually - the Mayans were never really concerned with the end date, but rather they celebrated each day as being unique and having a theme to it.
A great video to watch on the Mayan Calendar is here:
http://video.google.com/videoplay?docid=-8689261981090121097&ei=zZReS-LEJIqaqAO0yqAh&q=the+mayan+calendar+comes+north#It was done by Ian Lungold who met up with Dr. Carl Johan Calleman. I think it's great because it helps spread the truth about the Mayans and not just more spreading of fear about the world ending.
If nothing else, watch the first 20 minutes of the video as it has some wonderful information on what a calendar is!