The City of Ember - book/movie comparison

Shhhhhh.  Don't tell anyone, but I can be a little bit of a nerd sometimes.  I absolutely love this book series by Jean DuPrau.  I've read all of the books except The Diamond of Darkhold and that's on my estival reading list.  I read The City of Ember several years ago so I had to quickly read it again to refresh my memory a bit.  As a reward for my students we watched the feature film the last week of school.  They were mesmerized - especially the boys.  I remember when the movie came out that the reviews were not all that great, but I really enjoyed it.  I'm glad I waited for it to come out on DVD though - it wasn't $7.50 great.  There were many, many differences between the two works.  For example, when the main characters, Lina and Doon, make it to safety they throw the instructions for getting out of Ember down attached to a rock.  In the book, Lina's caretaker (a lady) finds the instructions.  However, the movie version has Doon's father finding the instructions.  Another difference is the inclusion of a giant mole in the film - strange.  The giant mole is eventually the demise of the crooked Mayor of Ember played by Bill Murray.  One of the grossest parts of the movie is where the mayor is gorging himself on canned sardines - he's almost chubby and the townspeople are scrawny and starving.  Murray's character is hoarding food while the citizens of Ember are starving as supplies are beginning to run low. The general story line is the same.  The generator that produces the town's electricity is well past it's prime since the "Builders" intended the people of Ember to come out after 200 years, and it is nearly 50 years over.  Overall, if you like the book series I think you would enjoy the movie.   My students did.