Not really a Visio diagram, but a flowchart nonetheless from the icanhascheezburger.com site (aka: the LOL Cats guys).
It's a Horse! (http://graphjam.memebase.com/2009/04/16/song-chart-memes-its-horse/)
The online build-a-silly-graphics tools are intriguing. You can try them at GraphJam (http://graphjam.com/)!
of the same tenor...
Source StumbleUpon / original unknown