Really? We're talking about leashes. Is it that big of a deal if your leash "tangles" up? I have never had a leash drastically interfere with my surfing; aside from catching on one of my ginormous fins, here and there. Stretch them, wrap them around your board, wear one as a belt, don't use one, etc - whatever you do, keep doing it. If you can't stand it "tangling," stop wearing one. After years and years of surfing developement, the "weight" (see pic from previous post) is the best thing the surfing pioneers have come up with.
BTW - has anyone had issues with the velcro they use on leashes? The velcro irritates the skin and it makes my session(s) very uncomfortable. (joke)