To me, there is nothing cooler than "needing" to use candles! I have several candle sconces around the house, and I can hardly wait for an excuse to use them. So, if the power ever goes out, it's fun to pretend like you're from another era.
If you have enough light to read by comfortably, try getting out one of the Little House books and float away to distant times with Laura and her family. Or choose another book like Harry Potter or something Tolkein-esque.
I have a couple of those new LED flashlights and I know exactly where they are, so I make sure everyone is equipped with one of these for restroom breaks, etc.
When the lights come back on, don't despair. Just flip the switches to the off positions and continue to enjoy this time with your kids. They're only little once, so make the most of it!
:0)