surely a waterproof digital watch is a must. one scenario i've not seen mentioned is a powercut while you are in the shower. what do you do without the light from your watch? no problem at home possibly, but at work or the gym? could you find your locker or your way out (and even then you'd be naked). a power cut can also be the result of a more serious catastrophe. suddenly you are naked with no gear at all in an earthquake/flood/fire......