The Cyalume SnapLight — a 6-inch chemical light stick that burns green for twelve hours. Bend it until the inner vial snaps, shake, and it lights.

The case for a glow stick over a torch is that there is nothing to go wrong. No battery to be flat, no bulb, no switch, no circuit to corrode. It works after sitting in a kit for years.

It is also non-sparking and safe around fuel, which a torch with a switch is not. That is why they live in ditch bags, fuel stores and vehicle kits.

Waterproof and it floats. Twelve hours covers a whole night.

In camp: mark guy lines so nobody takes a tent down at 2am, mark the path to the toilet, mark the turn-off so the late arrival finds you, give one to each child at dusk.

Under three dollars each. Buy a handful — they are single use, and the only mistake is cracking your last one.