The site poses problems in lateral or logical thinking, from easy to hard, with both hints and answers. Great party conversation and something kids will like.
how-to videos or, more commonly, audio/slideshows; useful rhetorically for both technical writing and instructional video learning; web2.0 sharing of video that is perhaps instructionally more useful than YouTube.
useful for teachers making clips to analyze in class; "personalize any video with your story. With visual spotlights, you can narrate your personal videos, add captions or subtitles, or comment on any scene."