Youtube is a veritable mine of videos, both home and professional, and I know some people get lost for hours in it, just looking for videos and watching them.
My SIL watches MTVs there. My BIL watches concert segments there... and lots of Japanese TV programs that get him laughing. I, however, cannot seem to get the hang of it because I can't seem to be able to come up with the right keywords. Plus, there is NO KEYWORD COMMENT ON YOUTUBE VIDEO. Sometimes, you'd only learn of a good video (say, that of Howie Mandel giving away free Xbox to strangers) through friends forwarding the youtube link.
But it doesn't mean getting sidetracked to other videos isn't an adventure in itself.