Even the great Nikola Tesla would have to be proud of man's amazing mastery of electric power these days. But for the gadget-loving road warrior you can never have enough power when you're on the move.
If you've never considered your options for taking spare power with you when you're on the move, there is now a great selection to pack away for a rainy day.
Companies like Belkin, Mophie, HyperJuice and others now make great little power packs that you can charge up via USB and just keep them in your bag for that day when you're pushing the limits that little bit harder. Just bring your standard USB charging cable and you're covered. You can buy them nice and small to just top up a phone, or you can find big ones to give your laptop a boost or keep a phone charged for a week.
You can spend in the $50 ballpark for a small power pack, or a few hundred dollars for a serious friend for your laptop.