Here are some cool mashups. I particularly like the whistling one.
The Kleptones invite you to take a journey "From Detroit To J.A."
Monkey/Beatles I'm a Believer/Paperback Writer video
Whistler's Delight mashup mixes 22 whistling songs
Incredible Beatles mashup mixes 40+ different tracks
I found these and others at the sometimes funny, always irreverent, and very ADULT ORIENTED
Boing Boing site.