I use a cheap nylon travel wallet with a Velcro closure (noisy to open) attached to a metal chain to attach it to a leather belt loop on my belt (sort of biker style...). I carry only a minimum of cards and cash that I 'must' have that day and leave the remainder in my hotel safe. If I have small denomination notes for tips etc I keep these separately in an old money clip in a pocket so as to reduce the number of times that my wallet has to come out into the open.