It's inevitable: At some point during a busy day of business travel, your smartphone is going to run out of juice -- usually when you don't have access to a wall outlet. While some smartphone owners can drop in a spare battery, others (who use, say, Apple's iPhone or Motorola's Droid Razr) don't have that option. Their best plan is to get a mobile charger.
Mobile chargers vary greatly in capacity, size, style and price. Most can charge your phone and other small devices, and some can also handle tablets (but not laptops). Arranged from largest capacity to lowest, here's an array of chargers to get you and your phone through the day.