Glowsticks!
GREAT Thread! I am a huge fan of glowsticks!
We keep one in every room of the house for power outages- they're perfect for the kids during storms. Our house rule is any drawer a glowstick is in, it's on the left front side. Lights out, just grope till you find a drawer, then feel the left side to see if a glowstick is there.
I love glowsticks because the kids can't burn the house down with them. When I was a kid, my dad had all these great kerosene lamps. But they were on the dangerous side, and not very portable.
We also stock flashlights- but they require batteries, or cranking, and don't put out the same light. Glowsticks are especially useful for the bathroom in a storm.
As for shelf life, I've found the coleman ones lasted over a year- when stored in a cool place. One I had in the glove box of the car got too hot and cracked open when broke, spraying the floor with Predator (1987) blood.
Target frequently sells these for $1, but they tend to go bad within a few months, I learned.
We also use glowsticks at halloween- we put them out instead of candles in our plastic pumpkins. No danger of a kid tipping over a candle, and the blue ones make eery, spectral lighting for the holiday.
I'd like to note one particular subject no one's addressed- toxicity.
My eldest daughter thought bending one back and forth after it had been lit for a few hours would brighten it (she was like 6 at the time). A hairline crack opened up, spraying her face with the contents.
She started screaming as it had got in her eye. We rushed her to the bathroom and started flushing her eye. Problem was it hurt so bad she couldn't open them. I knew glass hadn't escaped, but I was concerned about the chemical.
When we had her calmed down and most of it rinsed out, I called poison control. They didn't know what a cyalume nor glow stick was, and said they'd call back. Similarly, our doctor didn't know either, and suggested we take her to the E.R.
Poison control called back and said it was nontoxic but we needed to fully flush her eye out. Since our Doc had said the E.R., we went there...
And they didn't know what a glowstick was, either. (The ER Doc particularly didn't like me having to explain it to him either).
They ended up putting this contact-lens-like cap in my daughters eye, connected to a tube and flushed her eye out over a half hour period.
Later, I read up on the internet and learned no danger from the chemicals in her eye- she just needed to rinse out, something we had done at home.
Moral of the story is, be careful with these- they can rupture and the contents (apparently) burn like hell in your eye. Also bear in mind that there's a small glass ampule in the stick, containing one chemical. When you bend the stick, the ampule breaks, allowing the two chemicals to mix. Heat and light ensue.
Oh, and glowstick contents do fade away on a beige carpet in only a couple of days.
By the way, a first aid kit we recentyly bought at Target did have a glowstick in it as well.