I carry a Petzel E-lite and a Princeton-Tec "Pulsar" coin light with a slide-type on/off switch. I took the clip off of the E-lite to save a few grams but kept the head strap.

I use the Pulsar the most; for rummaging around in stow sacks after dark and such.

I have used the E-lite for hiking at night and for cooking after dark; it more than meets my needs. Actually, I have hiked using the Pulsar and was able to find my way. But mostly, there is light enough at night for me to hike w/o a light unless it is cloudy, or I am hiking under a thick forest canopy, or it is warm enough for rattlesnakes to be out.

I carry spare batteries for both: 0.75 oz with packaging.