Blubbr is a cool web tool that allows users to create quizzes around YouTube videos. These are basically interactive video quizzes ( called Trivs ) that you can create for your students and which they can answer while they watch the selected video clip. The quizzes are also feedback supported meaning students will get feedback as they answer each question.
http://www.educatorstechnology.com/2013/02/blubbr-great-tool-to-create-quizzes.html