Both American Sign Language and Plains Indian Sign Language are independent of spoken language. But ASL is a complete language equal in power to spoken language. Plains Indian Sign Language is probably a trade language – reduced in scope, more iconic than abstract.
Very interesting set of videos on Plains Indian Sign Language: http://www.youtube.com/watch?v=JST8l3ilsSQ
I’m a big fan now of b storm – the repetition of signs in his Marilyn Manson cover is interesting and I like the way pitch is represented in the ‘0h, 0h, 0h’ section of Pump It: http://www.youtube.com/user/st0rmfx
I’m a big fan of myhappyhands: http://www.youtube.com/user/MyHappyHands