Animoto

My students recently used Animoto to turn still pictures into a video clip. They were able to add their own music to their creation.  Animoto is free for the basic service and that is what we used.  These videos can then be shared on Facebook or YouTube.  You have complete control over your effects, backgrounds, and transitions.  The problem we ran into with the free version was the kids could only create 30 second videos.  They were disappointed at that.  As a teacher, that's not a bad thing.  When you have a lot of videos to grade, limiting each to 30 seconds can really be a life saver.

http://animoto.com/