An alarm clock you have to shoot with a laser gun in order to deactivate. Seems like it would be good for making sure you’re awake, and also learning to get your sight picture and aim after being suddenly woken up.
Of course, you’re going to want to make sure you’re picking up the laser gun to turn off the Gun O’Clock alarm clock. Rumor has it other guns will silence the alarm too, but run the risk of substantial collateral damage.