Originally Posted by Black_Thrym

Yay! I got it...I heard a similar one on Yugioh (don't stone me):

You're walking and there is a fork in the road. One path leads to the village of liars, the other to the village of truthtellers. The sign has been blown off, and you don't know the way. You meet a peasant walking from one of the paths. You may ask him one question in order to get to the village of the truthtellers. What will you ask?