I am already a fan of YouTube and play there erratically. I used to to learn about web 2.0 and found some great Second Life tutorials there. Here is a very interesting music video I found, the first I've seen about libraries. A little stereotypical, but fun anyway.
Here is a link to a video taken from SNL last season. It is Justin Timberlake and one of the cast doing a so-bad-it's-funny video. It might be offensive to some viewers.