You tube is always interesting. It can also be helpful. At Christmas I was supposed to sing a song in our Church Cantata entitled, "Who Could Imagine a King." Well, I didn't have any piano to practice to see what it sounded like. I was going to head to church to plunk out the melody on the piano there and then I thought - "I wonder if You Tube has anything." So I went on You Tube and put in the name of the song. There it was - Whitney Houston singing the song. I listened a few times to really get the melody and then did my own rendition. Whitney Houston I'm not, but everyone said I did well.
All of these sites like You Tube and Flickr are overwhelming with all the information they hold. I'm still not sure of the best way to search for things on the sites. Libraries might be able to use You tube for informational videos or tutorials. If there is something there, they could link to the instruction or do their own and put it up and link to it that way.
I like the video called Crazy Worms. It just made me smile. It's well synced with the music. Hope, if you're looking at this, it makes you smile too.