If you haven't figured it out yet, I moved this discussion out of the "funny pictures" thread since it was a bit of a topic derailment.
As for the $1M potato, Rothko painting, Michelangelo's David, Van Gogh's Starry Night, Serrano's "
Piss Christ", et. al. ... Artists, critics, scholars, patrons, politicians, clergy, gurus, shamans and old ladies have been trying to define "what is art" since the first wildebeest was scratched into a cave wall. More has ever been written about art than art that has been created. It's a moving target and will always be out of reach.
The idea of art as a valuable object is a relatively recent concept and art as expression or existence for it's own sake, especially in abstraction, is even younger. When applying modern beliefs out of historical context, some art becomes misunderstood and often foolish.
Just consider that many works now considered to be great masterpieces were considered crap in their own times, or were created for other reasons than the edification of artist, patron or subject.
Let me throw out an artist (or more to the point, let me throw him under the bus

).
Keith Haring. I knew him personally, although not very well. I met him on numerous occasions while in art school and my impression was that he was an ass. His art was simplistic and obvious, lacked much craft and pandered to the pseudo-intellectuals in the artistic community. His images are now being used extensively for their commercial value in manners which conflict with his early ideals, or used as fundraising for organizations that would have condemned him personally before he (his work) was famous. Is it STILL art if it's being used for something other than it's intended purposes? (<-rhetorical)
So there's a penny's worth of my $0.02.