The Pak-Lite is a minimalist flashlight consisting of a tiny LED snap-on attachment and a regular 9-volt battery. Used by the U.S. military and professional rescuers, the Pak-Lite ($13-$30) can survive a 250-foot drop, works in sub-zero temperatures, and will shine for more than 1,000 hours on one battery. And you’ll probably never need to replace the LED bulbs — they last about 100,000 hours (over 11 years continuously).