I've recently fallen in love with a new way to make animated slideshow videos out of still images: Animoto.com. Standard users can make unlimited 30-second videos, and for a small fee you can upgrade to an "All-Access" pass, allowing you to make 60-second videos. What I just recently learned, however, is that they are offering classroom teachers a "Classroom Code" that'll give each of your students a free All-Access pass (unlimited full-length videos for a whole year) so they can make Animotos videos for classroom projects. A full description of the education offer(as well as links to some samples) can be found here.
Here's a sample video I made of some photos I took on my recent trip to the Cannes Film Festival: