Get yourself a
SSSCAT and set it up near the 360. We use one here for our ever-nosy cat and it's great for keeping him off counters and, yes, away from our game consoles (he loves to check out our "phat" 360 when it's on). It's worth the money.
The one major drawback of SSSCAT is that it's really easy for humans to set off, too... well, me and my husband, at least
If it is the warmth that's luring your cat to your 360, a blanket might help, too. We always keep a blanket in the living room, usually on or near the sofa. Our cat often likes to curl up on it and nap next to us when we're playing games.