Pranks...

This weekend my brother-in-law and his girl friend are coming over.  I love when he comes and visits.  I get to act like I am much younger than I am.  One of those bonding moments that my wife's brother and I typically have is when we prank each other.  It has never really escalated to anything major but we love the bragging rights.  Typically I wait until the last night to get him so he doesn't have a chance to get me back until the next time we see him.  A couple examples of this might be...

.01 short sheeting his bed- This is when you take the bottom of the sheets and tuck them at the head of the bed.  You then pull the top of the sheets out and fold them in half towards the head of the bed again.  This causes the persons body to be sandwiched between 1 sheet.  Its actually pretty funny to watch them push and pull against themselves at the same time.

.02 dropping water from above- This was when he and his girl friend were sitting below the wooden deck I was standing on.  It came to my attention that I could pour water down on them.  With the help of Em's mom we both soaked them.  This ended in a water balloon fight at which I also soaked him good.  

These are just a few examples.  Here's where you come in.  Do you have any suggestions for good pranks I could pull on my brother-in-law?