Geek up the entrance to your home by adding an enter key doormat to your front stoop. The enter key doormat is styled like the enter key you'd see on a QWERTY keyboard. You can try to convince guests that jumping on the key will open your door, too.
Did I leave the flat iron on? Outlet that can be turned off with your smartphone even when you're not home. Oh wow that is great for my obsessive thoughts that I get when I leave the house! Oh did I turn the oven off? Did I turn the curling iron off?