There are a good few differences between the book and the movie but not so many that you are lost.
The bond these friends have is the most special thing about the story .The story is told in sections where we get a glimpse of each girl and what is going on in her life as the jeans pass to each of them.
Each girl documents what happened while wearing the jeans and then passes them on. By the end of the book these are one well travelled pair of jeans and their own bond is even closer then before. A lovely story , perfect for summer reading for anyone looking for a YA read.