Boot Socks - Two or three pairs of heavy woolen socks. Moleskin - Practically everyone needs this for blistered feet during the first week. Pocketknife - Swiss Army Knives are nice, but not absolutely necessary. Tweezers - You will use these mostly to remove cactus needles from each other's fannies. Sunscreen, chapstick, etc .
Ultraviolet damage is much greater in the thinner atmosphere of Colorado.
For those of you who still have hair. Lamps - Good for reading in bed. Gloves - For a cold morning. Musical instruments - Guitars, tubas, etc. Personal stereos - Walkman, etc.