I'm going to show you how you can annoy a mac user using only a couple simple parts.
Macs have a built in IR sensor that allows you to control them using an apple remote, this makes them an easy target for this prank. We will be using an arduino with the apple remote library to randomly "press buttons."
The arduino will act like an apple remote and at a random interval it will "press" a random button, this will either be back, forward or menu, this can easily be changed in the sketch though.
Update (22/03/10) I have added a sketch that will first wait 5 minutes, to give you time to hide the arduino and will then randomly "press" any button every 0.5 seconds, this is sure to drive your target crazy!
Step 1: The IR sensor.
On the imac the sensor is hiding behind the black edge around the screen, right above the apple logo.
On the macbook pro it is on the right side of the front on the bottom half, it looks like a black line.
On the macbook it is in the same location, but here it's a black dot.