30 Day D&D Challenge - Day 13 - Favorite Trap/Puzzle

Note - This post is part of the 30 Day D&D Challenge.

Day 13 - Favorite Trap/Puzzle

I'm heavily into miniatures and props, so I'm drawn toward any cool visual display of the trap or puzzle.  I saw on Penny Arcade where they used a laser pointer for a mirror puzzle; I thought that was pretty nifty.  I even stole the idea for my "Sunken Temple of Pelor" module, but I never got a chance to run it.  That module later evolved into "Zombie Cyborgs from Outer Space", but the laser puzzle didn't make the transition.

As a DM, though, I don't usually use a lot of puzzles or traps.  I'm too nice, and traps often come across as random DM jerkiness.  Sometimes it's like, "You didn't actually SAY you were staring ahead of you while you were walking down the hallway, so now you've fallen into a pit trap, OKAY?"  (I'm so glad passive perception was invented.)  I don't tend to put a lot of puzzles in my modules either, other than the "this door's key is held by a villain all the way on the opposite side of the dungeon" type.  I did make a few traps and puzzles in my "Temple of Elemental Weevils" session, but none of them were particularly difficult.