Re: LLAMA is your friend.
We already have it. It vibrates differently if you are getting a call, or if it's in Google Maps and you've nearly reached your next turn (for example).
Or did you mean custom vibrator? When the first iMac came out with the clear plastic, I remember mock adverts for the iBrator which was a see through vibrator. I'm sure Apple brand police hated that anyone would think such unpure thoughts, but it made me chuckle.