It's amazing to me that this part of the story hasn't gotten more attention. The most inflammatory of the cartoons were faked - by Islamists. They conned the BBC for a while:
Twelve cartoons were originally published by Jyllands-Posten. None showed the Prophet with the face of a pig. Yet such a portrayal has circulated in the Middle East (The BBC was caught out and for a time showed film of this in Gaza without realizing it was not one of the 12).
This picture, a fuzzy grey photocopy, can now be traced back (suspicion having been confirmed by an admission) to a delegation of Danish Muslim leaders who went to the Middle East in November to publicise the cartoons. The visit was organised by Abu Laban, a leading Muslim figure in Denmark.
According to the Danish paper Ekstra Bladet, the delegation took along a pamphlet showing the 12 drawings. But the delegation also showed a number of other pictures, including the "pig" one. The delegation claimed they were the sort of insults that Muslims in Denmark had to endure. These also got into circulation.
Here's the source for one of the cartoons: from the French Pig-Squealing Championships in Trie-sur-Baise's annual festival. Much of this controversy has been deliberately created by Islamists to polarize the world and to intimidate Western governments. Another reason to expose it for what it is.