it's ages since I have used it, but it is lovely on the feet and and any bits liable to sweat, especially in the hot weather..
It wouldn't stop you sweating though would it? If I had sweaty feet on a hot day I'd rather not have them coated in a kind of powdery paste.
Bloody hell this was a joke thread but I have just googled talcum powder and there all sorts of law suits and questions going on about whether it causes ovarian cancer.