i just got back from a hardcore 4 day backpacking trip (the "Alpine Lakes High Route"). i dangled from a 1000 foot cliff by a tree root with a full pack on my back while searching for the elusive Iron Cap Pass, no real trails for miles in any direction. we would gain or lose 500 - 1000 feet of elevation several times a day, up and down up and down up and down, ridge after ridge after ridge. The whole trip was almost 30 miles.
http://picasaweb.google.com/rhiydpus/TalusTarnsAndCairns# the middle pics show the epic "high route" stuff. one of my toes is still kind of numb.