But then there is the concept of the Vapor Barrier. The article does and I certainly agree about the waterproof jacket on the outside of bike clothes will be drenched in no time is basically a vapor barrier further from the skin, but the concept of a vapor barrier as close to the skin is contrary to the breathable aspect.

I haven't tried it yet, but there are a bunch of backpackers and hikers who swear by it.

Article on vapor barrier

Jay