Educanon is a program that allows you have students watch videos and answer questions along the way. You can insert questions into the video timeline so the video will pause while you check comprehension, test vocabulary, concept check etc. You can use your own videos or add questions to any video from the internet - a TED Talk for example!
I love that students get to work at their own pace and the teacher gets to see students' comprehension of a topic.
(update: Educanon is now Playpostit)