voicethread

A voicethread is a multimedia device that can hold videos, images and other documents. Using voicetrhead you can comment, navigate to other pages and share them with others. There are other applications when using voicethreads as well, such as being able to doodle on a slide, pick which comments you want shown and be exported to dvds or mp3s.
I don't think I would use voicethread just to show a video. If I was going to create other accounts for the students for a project or we would use it year around I think I could use it, but not for a one time thing. The cost is relatively low for the biggest package for K-12 education at only $60 a year, and would be a good investment if you were to use it often.