http://www.usatoday.com/tech/science/environment/2010-02-02-Avatar02_ST_N.htm

I found it interesting to hear how they maintain the 3D glasses, after you drop them off. They take them to a 3D Glasses-washing place, and are washed at a temp. of over 100 deg.! The glasses are $50 a pair, requiring batteries for a built-in security alarm. Who knew all this would go into something like 3D glasses!