I highly recommend these links, despite the fact that they don't directly pertain to music. However, they do pertain to mischief, which is the pinnacle of Metal art.
http://www.viruscomix.com/ Not bad, for the internet. Witty, quirky, and occasionally obscene, Subnormality is a clever and entertaining webcomic.
www.cracked.com More irreverent fun, some of which is quite brainy. I've wasted several consecutive hours on these satirical videos and articles.
www.perseus.com Ancient Greek Texts have never been so accessable. Tons of classics are available in their original languages, as well as their English translations.
http://www.picturesofwalls.com/ Documentation of cool graffiti. The legible kind.
http://flipskateboards.com/ One of the best Skateboard companies of which I know. Nice videos.