There are so many video resources available on the Internet.
Here is one i found on TeacherTube. I thought this would be cute to show a class of students learning the letter sounds. Kids this age would enjoy seeing other children perform and then they could create a video of themselves after they learn it.
Another is called Why does the moon look like it changes? from neok12 site. This would be good to use with a science lesson on the phases of the moon. The class could then make up their own questions to "ask an astronomer." I really liked all the categories on this site and it was fun to look around here.