Animoto is a service that combines your images and music and automatically creates a music video for you. When you are ready to work with your students with Animoto, make sure that use Animoto for Education site to sign up your school, though you do have to renew this every six months.

Here is an Animoto show I created using voiceovers and music.

Create your own video slideshow at animoto.com.

Here's another example this time from a student

Create your own video slideshow at animoto.com.

Animoto for Educators has some other examples of Animoto in use by teachers and students.

FlixTime is another similar tool.