I have an iPhone 3G with an incase slider case. I love the case but would like a holder/case to wear around my arms as I run by the lake at my apartment and lift weights in the gym. I can't believe that no one else has this desire to not have to take there iPhone out of one case to put it in another every time they work out. Surely there is a case that can do such a thing? Does anyone know of any? The Apple Store didn't have any that I could find. Thanks!