Animoto is a simple program online to create simple videos from pictures, sound, text, and existing video clips. It makes it possible to quickly create a video using still images, music, and text. Animoto is constantly updating its features as well as background options for your video slideshow. If you can make a slideshow presentation, you can make a video using Animoto Video Slideshows.
Animoto Video Slideshows limits you to 30 second videos, but you can create longer videos if you apply for an education account and give your students the teacher code. I love to use Animoto early in the school year to introduce my new students to some of the basic skills that will be carried across to more complex video creations later in the year such as Garage Band and iMovie.
Here is a sample assignment and a here is a sample student project: VFW- Interest Group Project