I believe it's been mentioned here before that Evan loves spinning on the kitchen floor (see Exhibit A, below).
Tonight, Jeremy and I were taking advantage of this love to teach Evan to sign "more." We would spin him a couple times, then stop, sign "more," and make the sign with his hands before spinning him another couple of times. Jeremy casually mentioned that Evan's diaper was wet, and I said I would take care of it in a minute.
I left the kitchen for a little bit, and then came back to get the "more"/spin game going again. I started to spin Evan, and I notice he's "sticking" and not spinning freely like he was before. I rolled him over a bit, and there was a wet diaper balled up next to him. I figured Jeremy was just playing a trick on me because I hadn't changed Evan right away. But Jeremy said he didn't do it. So I unsnapped Evan's overalls. And he was completely naked underneath--no diaper!
Evidently, all that spinning had worked the diaper off. I have no idea how it got out of his pants though, because all the leg snaps were closed... I rediapered Evan, and we called it a night on the spinning game.