A visualization of why 1/4 + 1/16 + 1/64 + 1/256 + ... = 1/3
I like this one better.
<a href="http://web.mat.bham.ac.uk/pgweb/random/2009/04/proof-without-words/" rel="nofollow">http://web.mat.bham.ac.uk/pgweb/random/2009/04/proof-without...</a>