EDpuzzle is a neat tool that allows you to add your voice and text questions to educational videos. On EDpuzzle you can search for educational videos and or upload your own videos to use as the basis of your lesson.
A superb site where you can crop YouTube & other online videos, add audio messages and quiz questions which provide individual assessment feedback to check understanding of your students.
http://ictmagic.wikispaces.com/ICT+%26+Web+Tools