Phubby - the active wearWrist Cubby / Arm Wallet for cell Phone / iPod / PDA with 'touch' technology
I love my phubby for cash, credit cards, identification but I didn't like my cell phone in it. It is great for travel or shopping.  It isn't not noticeable on your wrist and very comfortable.  Very secure. I think a smaller phone might work but mine is a larger slide phone.  I have several different colors to coordinate with my shirts.