"If the entire earth, land and water, were covered with computers, 
IPv6 would allow 7x10^23 IP addresses per square meter.  [...]  While it
was not the intention to give every molecule on the surface of the earth
its own IP address, we are not that far off."
	-- Tannenbaum, _Computer_Networks_, 3rd Edition
(Courtesy of Joseph Pingenot <jap3003@ksu.edu>)