Self Cleaning Cloth
In the 1951 film "The Man in the White Suit", "a man invents a fabric that won't get dirty or wear out, but he seems to have made more enemies than friends in the process" [imdb]. In the more modern sci-fi novel, "The Diamond Age", one of the characters uses a pair of white gloves that are self cleaning.
Following fiction, "..scientists at Hong Kong Polytechnic University coated cotton with nanoparticles of titanium dioxide. When subjected to ultraviolet light, the titanium dioxide produces an oxidizing agent that can break down dirt and other organic substances." [boingboing]
In addition, the scientists say "...after a few days in the sunshine, or even indoor light, the dirt [from our clothing] will disappear." Quite a leap from odor free socks or stain resistant pants.
[Link via boingboing]