LaRue Tactical has announced their now carrying the Armageddon Gear Carbine Sling. It is described as giving the operator the "...ultimate utility in allowing the rifle to be ready for action without sling adjustment while being securely held against the body for hands-free tasks and freedom of movement. This sling provides the ultimate in weapon stability by pulling the rifle back into the shoulder creating a very stable shooting position."
The Armageddon Gear Carbine Sling has a simple, tubular design and is currently available only in Coyote Brown. It has stretch points on the load-bearing and stress locations, a quick release mechanism and lifetime warranty.
Granted, a sling is a sling is a sling (though some are substantially more complicated than others) but this one does have a certain utilitarian appeal.
If you're not familiar with them, Armageddon Gear is online here.