Adidas knows footwear, and they are smokin' the midnight oil to bring you some of the absolutely lightest doghouses out there. The Adidas Clima Ride TR trail shoe weighs in 20oz per pair for a size ten.
The mesh upper on the TR combines with the light weight to make it feel more like a pair of socks, but it will take the punishment of trail running or fast hiking. The cushioning is minimal but sufficient for normal feet, and the sole is grippy enough to let you get up and go when the going gets loose, muddy, sandy or otherwise low-traction.
Adidas is making a serious effort at the outdoor market, and you shouldn't hesitate to try the Clima Ride TR if you're looking for some uberlight, hyperbreathable courage for your feet.