I'm in love with baby powder. Well I like it a lot!
I use the cornstarch powder too, it feels way nicer.
I use it after nappy changes cos it smells nice and I am certain that he is nice and dry. I have used it under the chin/on neck too, babies make it quite difficult to get in there to dry it off properly.
I use it for me too under the boobies and between the thighs in summer time can't live without it