Ha! Yeah, I've seen that happen a few times, too. Halvah's done it before...she's inordinately fond of the bathroom sink, even though it's rare that it's left dripping.
She'll even sleep in there. Doesn't strike me as a comfy spot, but then, I'm not a cat...so what do I know?
Tam likes hiding in the tub, too. I've had him pop out and stare at me a couple times.
It's just the perfect size for a cat to curl up in.