How to Make Your Sliding Patio Door Close Automatically [VIDEO]

This is another one of those tricks that doesn't apply to me just yet (since I don't have a sliding patio door); but I had to share it anyway because it's just that cool!

This one's all about weights and counterweights.  Sure, you might have to go buy a pulley from the hardware store, but it would probably pay for itself with what you'll save on utility bills!