For a while now we've been using Animoto and to great effect. There are a bunch of creative guys behind the site and this shows in the way that the movies (photo stories if you like) get spliced together. Essentially, they are randomised according to the music you wish to use.
At school we decided to make a club for the more creative kids in our school first. The reason we do this is to iron out the kinks first - not to make an elitest group. The great thing about making a club is that the kids that attend the club become your in-class experts and helpers when things inevitable go awry! Just make sure you select the kids in your classes ;)
How to Create a Video in Animoto?
If you had more than 15 images Animoto will warn you that you some images might get cut off or you can choose the full length version.
The great thing about Animoto is furthered by it's iPod app and the Education log in. The education edition allows several features of the fully fledged animoto edition - namely unlimited slide shows to be uploaded. To access the education edition you have to prove youare an educational establishment and you are who you say you are.
Lastly, Animoto gives you the option of HD. So, should you be a keen photographer and you know the images you have deserve to be in HD then there is this option. Perhaps then use them on Vimeo?