Often, a YouTube video would complement an already great answer. For example, this MythBuster video would make a great addition to this question. As they say, seeing is believing. It's only one example amongst many. It is possible to have YouTube support enabled to enhance user experience?
Note: If it does get implement, YouTube videos will get threaded the same way as any outgoing links: they are nice, but the answer must be hosted here most and foremost.