Patio screen doors are fantastic at letting the breeze in and crucial in blocking insect intruders. But in a perfect world, we wouldn't even need them. In the real world, they'd somehow close themselves so we wouldn't be bothered with them. We can make that happen. Genius Clan McArthur rigged his screen door so it automatically closes. It's so easy you can do it too.

McArthur set up his automatic closing screen door by using a water bottle, a pivot pulley and a piece of string. Slide the door open and the door automatically closes from the weight of the water bottle. It's so simple that dogs can even use it (the real reason McArthur built it up in the first place), they just nose their way inside and watch the doors close behind them. [Clan McArthur via Viral Viral Videos]