Latest Immature thing you did? (Page 3)

We just got this laser pointer for the cat.  I have been messing with people from the 15th floor of my apartment as they walk by on the street.  It makes me laugh even more becuase I know how stupid it is.

 I once took 2 lbs of table sugar and funneled into the top of a guys locker at work. Another fun one I've heard of is to drill a hole and install a grease fitting on the victim's tool box or any locked object. Attach a pneumatic grease gun to the fitting and pump in a few pounds of grease then remove the fitting.