Oh wait - duh - I forgot the more important part of it. You
  don't care WHICH one is telling the truth and which one is
  lying. (I told ya I forgot how it went!). They're guards in
  front of two doors. You have to decide which door to go through.
  Let's say one door leads to heave,n, the other door leads to
  Hell. But they're labeled Door A and Door B. You ask them "If
  you were the liar, which door would you pick?" If they both say
  "Door B", you pick Door A. If They both pick door A, you choose
  door b. "