On the big screen you can stop someone from breaking into a room with a wooden chair jammed against the door. In reality, you might as well just hand intruders your keys unless you're using Daniel Ballou's specially engineered Who's There Chair.
The back of the chair's made from steel tubing so it's extra strong, while a pair of gripped pivoting feet on the back legs help keep it in place. There's even a notch in the backrest designed to perfectly fit a doorknob so the chair stays in place long enough for you to slip out the window and safely jump five stories into a dumpster full of cushioning boxes and trash bags below -- just like in the movies. [Daniel Ballou via bookofjoe]