We all know of at least one or two. Hell some of us have come up with our own, Whatever you have whether UFOs, bigfoot, or even killer sweaters made by North Koreans (yes it is out there) feel free to post it. Credibility isn't necessary, but you might get people calling you a dumb ass.
Interpretations of the Mayan calendar suggest that it is going to be the beggining of a new era as opposed to the ending of the world. I whole-heartedly agree with this.