How about water and oil proof clothing and gear?
I'm thinking this should almost be a must-have on everything you're wearing and using. I wonder - would this be required as an additional expenditure, or would this be built-in with everything automatically? I mean, seriously -- a car that doesn't get mud on it, and stays dry in the rain - and if your clothing has this, you can sit in a rainstorm, and not worry about getting soaked because your clothes won't absorb any of the water.