I have a suggestion for a NATAL "optional" object for feedback: a fork.
A fork would really be perfect for at least three reasons: it reminds both a Morrowind and a Planescape: Torment sidequests.
You can poke it in the eyes of innocent bystanders.
It remind me of a joke happened in my family decennia ago: in the late '20s or early '30s my maternal granny was passionately speaking about politics with her brothers and sisters-in-law, one of them nonchalantly handed her a fork and she absent-mindedly grabbed it and kept on speaking, widely gesticulating with that fork in the hand. When she stopped, finally she became aware of the fork, looked quite surprised for a moment, and everybody else burst into laughter.
And now, at last, thanks to NATAL Optional Fork™, everybody will be able to relive the same experience!
Hey, thinking of it, so my granny invented WiiMote and NATAL?