When every one else is sleeping, I contemplate things. I contemplated my navel for awhile, but I went to sleep doubled up. Not a good way to wake up, I might add.
other things to contemplate: using food colouring to dye your neighbour's yappie little white poodle shocking pink. It won't hurt the dog, but it sure will p*ss off your neighbour!
stuff an old pair of kid's boots top downwards in the grating of a storm drain. make it look like a kid might still be down there hanging by his feet.
build an anatomically correct male (or female) snow person on your neighbour's front lawn.
practice your drums on your back deck at 4:00 in the morning, preferably in the summer.
contemplate the stars by lying on your roof, depending on the pitch of your roof. if it's an 80 degree angle straight up, better use your lawn.