Don't ask me how I ever missed these before, but miss 'em I did! (Actually, perhaps "miss" is way too strong a word...)
"YTMND, an initialism for 'You're The Man Now, Dog!', is a website community that centers around the creation of YTMNDs, which are pages featuring a juxtaposition of a single image, optionally animated and/or tiled, along with large zooming text and a looping sound file. YTMND is also the general term used to describe any such site." (from "YTMND" in Wikipedia)
To tell you the truth, I had seen a "YTMND" before... I just didn't know it! It was the classic website http://www.khaaan.com/, sent to me by Tom, who - as I recall - wisecracked, "Marvel that somebody actually got a domain name for this!"
As far as I can tell, "YTMND" is something like an internet equivalent of Andy Warhol, highlighting the absurd in popular culture by repeating iconic images and phrases ad nauseum. But then again, I very well may just be reading way too much into it!
Anyway, while it seems that "YTMND" is mostly just one big in-joke after another, some actually are fairly humorous under any circumstances! For example...
But the latest fad on YTMND seems to be medieval themes, using the fun Historic Tale Construction Kit for the graphics. (As one user put cleverly put it on Monkeyfilter, "Son of a gun, gonna have big fun on the Bayeux!") Like taking the loop of the famous SNL sketch "What is love!?" and making the medieval version, What doth love be?
But, then again... verily, I doth be easily bemused! :-)