

The curiosities that you speak of are EL (Electro-Luminescent) pads.  They
are mostly used as backlights for LCD's, and as you pointed out, comes
in several different colors.  Many of them emit white-ish colors ("true"
white, and blue-whiteis-blue are the ones that I've personally encountered
the most often.)

They vary in their input requirements, however, they tend to operate at 
about 100 Vrms, and at much higher than 60 Hz.  (400 Hz to 1 kHz, if I 
recall correctly.)   You can get them to work at 120 Vrms, 60 Hz (i.e.,
line) but they don't glow as brightly, and they will degrade much faster.
(Oh yes, almost forgot, EL's have this tendency to wear out over time...)
