These are ideal for an emergency, or for when your flashlight dies unexpectedly.
As Lokidude mentioned the other day, candles are handy. The problem is that they spread their light all over (not always a problem), they're easy to blow out, and wind can make them hard to light. So here's a way around that.
Most cans have a domed bottom, so you may need to push the center of the dome down to create a better surface for the candle to sit on.
You can sit it on a table, or the ground, or bend the pull-tab up and use a wire to hang it. It'll direct the light where you want, and you can bend the wings in or out to help protect it from the wind.