| Dockers, the fine people who bring us all kinds of different pants, began marketing a line of pants in 2003 that claim to use nanotechnology in the battle of pants vs. stains. Hollywood has fed us images of nanotechnology begating all sorts of amazing robotic creations, so logically one could conclude that there are a team of trained microscopic robots on patrol within the fibers of your pants, ever vigilant in the fight against rogue liquids, right? Or perhaps Dockers has stolen some Borg technology from the world of Star Trek and has injected these pants with nanoprobes, thereby assimilating your garments to form a mighty pants collective that seeks out stains and takes their technology in a neverending quest for clothing perfection.
The real answer is much more mundane.
Fortune.com defines "nanotechnology" as "the science of building machines and materials at the molecular level, where key components are measured in nanometers." While such technology does give us those tiny little computer chips that do oh-so-amazing things, in the case of Dockers pants the nanotech in use is actually tiny little fibers that disallow spilled liquids from absorbing into the fabric, instead causing them to roll off on to your shoes (the liquids, not your pants). These special fibers do allow washing machine water to penetrate the pants in order to provide that deep cleaning action that we're all so accustomed to, however. There is also a Teflon coating on the garment that provides most of the stain fighting power. The pants require special cleaning as well: do not use powdered detergents or fabric softeners, press them after every fifth wash, and dry clean if desired.
So, in the end, there are no tiny little robots on patrol in your pants. Yet.
References:
http://www.metafilter.com
http://www.cnn.com/2003/TECH/ptech/07/18/popsci.nantech.pants/index.html | 
