These guys are hysterical. No, seriously. And they are actually talented musicians to go with it.
Have a look at this video of Tenacious D's guide to becoming a true rock and roll master.
A word of warning: The film "Pick of Destiny" is awesome and suitable for older children and adults that are not easily offended. The Tenacious DVD Complete Masterworks however is absolutely hysterical if you enjoy even more risky comedy. Not for the faint hearted. Leave your morals by the door as you sit down to enjoy this one!
They are awesome.
The Guitar Master
The Guitar Master
http://www.theguitarmaster.co.uk/staticpages/index.php/tenaciousd