Just when you thought Dan Brown has milked the Catholic Church of all its controversial conspiracy theories, here's another one that I've never heard of before until now. James Rollins' The Doomsday Key prominently features St. Malachy in its storyline.
St. Malachy is a 12th century Irish priest who became an archbishop. It is said that on a visit to the Vatican, he had a vision which allowed him to see the last 112 popes up to the end of the world. The list he came up with is supposed to be very accurate with the most disturbing part being, the current Pope (Benedict XVI), is supposed to be the 111th already. So if his prophecies are accurate, the next pope (Petrus Romanus) will be the last already and its end of the world!
Of course, there are several interpretations to his visions. One of them was that he did not clearly say Petrus Romanus will come immediately after Benedict. The loophole is that there could be several more popes between then.
In any case, there are several skeptics who debunk his vision as something that was fabricated to favor certain priests at that time, to be elected as Pope (hence making it a self-fulfilling prophecy). Here's a good site to visit to learn more about the skeptical views of St. Malachy's prophecies.
Admittedly, the way he describes the Popes in his vision is through their birthplaces or papal seals. He does not really give their specific names. So some people say that with enough imagination, you can force anybody to fit his predictions. Well, you be the judge after you check out the hyperlinked references in this blog entry.