Need to make your PowerPoint presentation more annoying? [How to embed YouTube videos in your next presentation](http://lifehacker.com/software/video-demonstration/embed-youtube-clips-in-a-powerpoint-presentation-292182.php).
Please, for the love of humanity, use this only for good, not evil. The golden rule of PowerPoint: if you don’t need it to make your point, don’t use it. Less is more. See the presentations of [Larry Lessig](http://lessig.org/content/av/) for some excellent examples.