QUOTE (bmann_340 @ January 5th 2009 3:36 PM)

do these use the ambient light that exists at night or do the "store" light that they are exposed to during the day? If they were kept in the dark (like a drawer) would they illuminate?
They do not use ambient light, they do not store light and yes they will illuminate if kept in a drawer. As Pepper stated the sight has small capsules that contain radioactive gas(Tritium, radioactive isotope of Hydrogen)), that emits a "glow" for several years, up to and sometimes past a decade.
I believe that Meprolight and Trijicon are the #1 manufactures of this type of sight. This technology is used in Trijicon and Meprolight reflex light and some of there other optics.