Some folks like to convert smal LED lights so they clip on a cap brim or a headband of elastic. For several years I have attached alligator clips to small LED lights such as Photons - using the screws on some models or a dab of ShoeGoo on others. Then a simple elastic strap with a pinch in it turns the light into a pivoting headlamp.

The trouble with Photons and other coin-battery LEDs is the short life and expense of the batteries. I like to read late. So....

I picked up a Pak-Lite Basic, a regulated, 2-LED, single-intensity light that fits on a 9-volt battery for $15 (battery included). I attached an alligator clip to a band of elastic that fits around the battery - but these batteries last so long it might be as practical to glue the clip on and just trash the clip with the battery. Anyway, instead of 3/5" elastic that will hold a Photon steady, I had to use 1" elastic to support the heavier 9-volt light. The rig weighs under 2 ounces, gives good light for about 30 - 35 hours and drops off gradually for another 30 or 40 - using an alky battery. Not a bad rig for late-nite readers, thruhikers and others who need long battery life and find a headlamp convenient.