I found this book very interesting, although it's kind of disgusting. If you're an oblivious person (like my sister : )) you might miss the innuendos!
It's basically about this group of sheep that moved into an abandoned town after all the humans died off, because the pastures were all dried up (I think). In one of the houses, a young sheep accidentally turned on a television, and, by watching movies & TV shows, the sheep learned to speak. They were soon basically humans, except, of course, they were sheep. After a while, the food was all gone from the supermarkets, and sheep were going hungry. After many robberies and riots, the leaders announced a delicious new food called Baaa. Baaa was very popular, but, mysteriously, as the demand for Baaa grew, the population declined. Baaa trucks were a common sight, driving around the neighborhoods with a sign that said "Free Rides." Finally, there were only two sheep left. And one day, they met for dinner.