Here are links to some products that can help when the power is out. This is not an endorsement of any kind, though this list has been contributed by members from among items they themselves have used.
Portable 12 volt jump starter
2.1 amp USB car charger
Low-cost flashlights with batteries
AA battery-powered USB charger
400 watt 12 volt DC to 120 volt AC power inverter
Portable toilet and waste bags
Candle lantern and spare candles
Brighter candle lantern, can also boil small amounts of water
Be sure to test any emergency equipment before you need it! If you're depending on something that's rechargeable, be sure to run it through a few recharge cycles before you need it, determine how long a charge will last for your typical use, keep it charged. Wikipedia has a good article here about how many recharge cycles different battery types can tolerate and how long they hold their charge when not in use. For items that require single-use batteries, like alkaline batteries, be sure to keep plenty of fresh spares on hand. Alkaline batteries typically have a shelf life of several years.