A new feature being tested out by Youtube could add infinitely many new uses to the video-hosting service. TechCrunch reports that called "Video Questions Editor Beta".
Youtube describes the feature as a way for "multiple questions to be displayed on top of your video during playback that a viewer can answer."
It's just in beta, and the feature may not end up being introduced or integrated at all. But, for now, some users can play around and get creative with the beta, which TC describes thusly:
It's pretty straightforward -- you just enter the question you want to ask, the point in the video when it should appear, and the answers that a viewer can choose from. You can also identify one of the answers as the correct one, and offer a hint if the viewers guess incorrectly. Afterwards, you can view a summary of the answers on your analytics page.