Caves
We were taking a guided tour of a cave. They didn't want any lawsuits, you know, so they'd gone and wired up the whole place.
One of the guys in the group asks, "how did people find their way around in this cave before they put lights in it?"
Lanterns, hello? The tour guide had probably heard this question a million times.
"Bio-illuminescence," our tour guide deadpanned. "Most people don't know this, but if you rub your hands together really fast, they'll let off a bit of a glow."
Then he turned out all the lights.
I then heard twenty people furiously rubbing their hands together.

(no, I didn't fall for it)

On a more general note, I see that you guys have been "enjoying" our "tourists".
^{For several years now, America has been packing up its dumbest citizens, outfitting them with cameras and faulty phrasebooks, and shipping over to Western Europe. We used to just send them all to Texas, but when one of them escaped and got elected president we realized that keeping them on the continent was not an option.}
(fantastic german, Mon 10 Jan 2005, 17:18, Reply)