I have a half-dozen pair of the same pants that I just rotate through: REI Adventures pants. They aren't "waterproof," but they are made from nylon and dry very quickly. Unlike most nylon/polyester pants, this style uses a "peached" fabric so it looks normal (cotton-like) and not shiny, and they don't make a swishing sound when you walk. They are good pants to ride and play in, but still dressy enough that I pair them with a sportscoat and wear them to court. (I'm a lawyer.) If you get rid of all the cotton stuff and switch over to wool and synthetics, rain isn't nearly as much of a problem.