I was reading through the Dec. 2007 copy of "Backpacker" magazine and came across an article on ultralight hiking. Some suggestions are to "Swap your knife for a razor blade; which is just as effective in most medical situations", also to, "Ditch the map" and to "Empty your (water) bottles". It goes on to say "Along many mountain trails, you rarely need to carry more than a liter -- if any."

I guess being prepared doesn't carry over to the trailhead for some.