I was using
them in a ring light for a downhole well camera.  Not that expe=
 nsive=2C about $6 each. 
 Has anyone ever tried them for flim photograhpy? THe data sheets I looked
 at showed a fairly continuous output spectrrum (unlike the pure colour
 LEDs, of course), which could presumably be filtered into something that
 looked like daylight to colour film. 
 
I use an array of white LEDs behind a polarizing filter in combination
with a second polarizer on my lens to minimize reflections from glossy
surfaces.
Peace...  Sridhar