OK, i just did another one.

Went into the ONLY mens room on our lower level and locked all the stalls shut from the inside. Neat little trick to this. Take toilet paper and twist it up ti make it look kinda like a rope. Then you loosely tie it around the latch (the slide style one... not the knob). Then you close the door and pull the TP through the crack. This pulls the latch and when it's done, the TP rips away effective locking the door without having to crawl under to climb over the walls.