Playing with Animoto. They have an "educator edition" now, that lets teachers have full-length versions for free.
Here's one I made with some photos I took while walking the dogs a few weeks ago.
Wouldn't this be a great tool for book reviews? Several of our classes are working on book reports right now. I'm going to talk to the teachers about using Animoto instead, have the students find related images, create voice and soundtrack in Garage Band, then link them to the library website for student book reviews.