Can you even turn it off? I'm sure it uses some power, but it wont be a noticeable amount.
It's easy enough to test if you have an Apple remote on hand: Put the computer to sleep and see if the remote will wake it--if yes, then it probably consumes a tiny amount of power. If not, then the IR hardware must be asleep.
I don't have one on hand to test myself. On the topic of pranks, I'm not sure that an Apple remote will actually do anything unless it's been paired with that Mac.
Funny aside on playing tricks with remotes: In the way old days Apple used to use the same remote codes as Sony. We had a Sony TV, and you could use its remote to mess with the volume of our Power Mac 6500... which of course at one point I did to mess with my brother, who wasn't aware of the ability.
It is purely a receiver, drawing a ridiculously minimal amount of power. For comparison, I used to have a Hewlett Packard calculator that had an IR transceiver (transmit and receive) and it ran for weeks on a set of triple-A batteries. (And I used the IR a lot, to transfer info to and from other students with an HP, to my small HP thermal printer, etc.)
Any Apple remote (or the few out there designed to work with Mac's over IR) will control any Apple computer, but you can lock your computer to only work with your remote. IIRC, just bring the remote close to the IR sensor, and hold down the menu and right arrow buttons for about 5 seconds, until you see a symbol pop up on the screen that looks like a remote and a lock. That way, no other remotes will be able to control your computer. Of course, it's even more effective to turn off IR, but that would prevent you from using a remote yourself. Only you can decide if that matters to you.
jW
IR... I thought that was a given in this conversation.Is the apple remote IR or bluetooth?