My best friend and I freaked her daughter out one time with that.
My BF was on the computer and I was reading a book when I had a thought.
Me: Hey, what's that guys name? You know who I'm talking about.
BF: O.o Shel Silverstein?
Me: Yes! Thanks!
BFD: What the hell, you guys?!?! That's creepy!
BFD twitched for ages...it was awesome.
. She is almost 20 now, they've lived with me for years, and she still finds it freaky when her mom and I speak in stereo or finish each others sentences.