Digital photography requires juice. In the good old days you could buy a film camera that ran off a single small battery and take pictures for months or years. Digital is a new beast, and while you won't need to take rolls of film with you anymore, you will need to make sure you've got plenty of power wherever you go.
These are some of the key items that will ensure that you can keep snapping pictures on the road:
Your camera's power adapter: Some cameras charge by plugging into an outlet via a charging cable. Prosumer and professional cameras often use an external charger (previous page); pop out the battery from the camera body's handgrip and dock it to the charger. Both the battery-charger and the external charger are must-bring items no matter where you're going.
Secondary battery: Most cameras have a removable battery. Some use rechargeable AAs, while others use specialized rechargeable cells available at camera stores (Figure 2.1).
Figure 2.1. Removable batteries.
If your camera uses AA batteries, see if it will take rechargeable ones, and pack those and a charger. You can use the rechargeable AA batteries to save on cost, but if you run out of power you can pop into any newspaper, hardware, or grocery store on the planet to get standard AA batteries. If you must use nonrechargeable batteries, Energizer Photo Lithium AAs are best because they're disposable.
Chargers for accessories: Don't forget that your cell phone, PDA, and any other electronic gizmo you bring along will need its own charger.
Computer power adapter and batteries: If you bring a laptop, keep in mind they are more power-hungry than a third-world dictator. You'll want your power cord and possibly an extra battery.
Travel adapters: Don't forget that not every country uses the same 110 volt power we do, or the same plugs. If you're traveling outside the United States you'll likely need a travel power converter (Figure 2.3).
Figure 2.2. A little research ahead of time will help you know what kind of power adapters and converters you might need for an overseas trip. (Photo by Reed Hoffman)
Figure 2.3. Car inverters are fairly inexpensive and can be plugged into the cigarette lighter outlet to enable you to charge batteries while on the road. (Photo by Reed Hoffmann)
Don't just buy a converter with a plug for the country you're going to, buy it with adapters for any nearby countries as well. I know people who have flown to England and then decided to take a trip to France and couldn't plug in chargers anywhere.
Power inverter: Many pros carry a power inverter (Figure 2.3), a specialized device that allows them to keep shooting when mere mortals are out of juice. They are available at Radio Shack, and other electronic stores. A power inverter has a 12 volt automobile cigarette lighter adapter on one end and a 110 volt outlet on the other. It turns your rental car into a mobile power plant.
Universal adapters: A few companies have started to make all-in-one power adapters that use interchangeable heads to power any number of items. These devices are also available at Radio Shack and other electronics stores. The only downside is that all your electricity comes through one single device. If it breaks you can't power anything.
Power strips: Take one. Many hotel and motel rooms only have one available outlet.
While it might seem like a good idea to put chargers and cables into your checked luggage while your camera gear stays in your carry-on, keep with you any chargers you can't shoot without. If your luggage gets lost, you'll still be able to take pictures.