The process by which you battle someone or group of friends by rattling off(via email, instant message, or verbally) funny youtube videos. A winner is decided after the most hilarious video is presented and a unanimous winner is chosen, or a challenger backs down.
My friends and I had a youtube off via email. Someone started by linking to the video "David at the Dentist", and I countered with "Everyday Normal Guy". In the end I won by linking to the "The 1987 Crystal Light National Aerobic Championship" which is by far the best youtube video ever.