You can click this link to make a storybook for a child you love. It works like madlibs - you fill in a few (4-8) bits of info, they make the book! Then, if you like it, you can even print it out and keep it!
I've done Cinderella and Incredibles for M and Toy Story 2 and Nemo for R. There are two more options, too! My kids love the ones I've printed so far, and I'll print another for each of them tomorrow. The only issues I've had are their instructions for assembling the printed book are kinda weird... and they assume your child's "friend" in the Cinderella story is a girl... which makes for some creative reading since it's her brother =)