Well, the ground work has been laid out for you, so feel free to gross out your friends/family/coworkers/foes :P For maximum creepiness, I recommend adding a s

Well, the ground work has been laid out for you, so feel free to gross out your friends/family/coworkers/foes :P For maximum creepiness, I recommend adding a small speaker. And a covert way to have it act perfectly normal, so you can say "it never does that for me" followed by a quick demonstration (most simple: have it misbehave with some chance, and then have it behave normally until a number of requests have been made or a timeout hit).