My friend Duane posted a note on his blog about GraphJam, so I started looking. My work in software for data analysis make some of these even more funny than they might already be.
The first one I saw was the Death Star, which is somewhat amusing:
I especially like the one about Mr. T and fools:
And this one is funny:
But so far, this one has us (5 co-workers and me) laughing hardest:
Some of them aren't particularly good, and some are very esoteric, but overall just brilliant.