Craig Mitich, 27, has spent 20 minutes searching his apartment for whatever the hell is emitting a high-pitched beep every few minutes. 'Okay, it's not my cell phone... it's not my microwave... or my car-alarm remote,' said Mitich, standing motionless with an ear cocked toward his entertainment center. 'God, what is it? Can a power strip beep?' At press time, Mitich was on his hands and knees, unplugging his appliances one by one. 