Ultra Sound

Grace: Mom what is that
Me: It is a picture of Jack when he was in my tummy.
Grace: ??
Me: The doctor took a picture of Jack when he was in my tummy, see here is his head, and his nose, and this is his foot.
Grace: (after much pondering) There can't be any fun things to do in there.

She may be right, unless you count growing finger nails.