So I, of course, immediately checked my all-time-favorite xkcd comics - the five-part barrel series. None of them had been done, so I decided to tackle my favorite, the culmination. It was a lot of fun - slicing, cloning, sorting, all of course in GIMP, and by the end I had a nice 3D version of the comic, so I sent it in, figuring that a million other geeks also held these comics near and dear, and at least a bunch of those had gotten around to it before me.
But this morning, I checked my email, and what do you know, I had a email that said "Thanks!" in reply to my submission, and sure enough, there was my 3D conversion, with my name at the bottom and everything! How cool is that?
So of course, I had to go through and convert the rest of the barrel series - If it's still April Fools', you may notice that all of them are now 3D. I sent them in about half an hour ago, and got a prompt reply saying they'd all been put up, and complementing me on dealing with the "slice-orthogonal plane". Awesome, and totally worth being a few minutes late to Engineering Probability and Stats for.