From the Wikipedia article on Animutation:
Animutation is a form of art using Macromedia Flash to create pop culture influenced videos of independent, mainstream, or foreign music. The style was popularized and invented by Neil Cicierega (aka Trapezoid) from Kingston, Massachusetts at the age of 13. The genre is currently expanding to include many other Flash artists. Independent musicians are turning to animutation artists and Flash-based music videos to promote their work for the Internet community. Currently a cult following near that of the also-popular YTMNDs, the genre has the potential to become mainstream within the next few years.
Over the years, TMBG has been found in these Animutations.
The Fingertips Project - Collaborative Flash animation for Fingertips in its entirety. Linnell and Flansburgh also come up as the random heads at the end.