My EDC is a PICO Light from EGear. Designed by some guy named Doug (I can't read the rest from my 10 or 15 of them ;-) For a headlamp (EDC carry) I have several EQ2, also from EGear. Those of Doug's design are better than the standard one, but both are great for those times you did not think you needed a light.

I have larger headlamps in my gear for outdoor use and in the bags in cars and at home.

The best,

Jerry