This multiuse portable cellphone charger is a third the size of conventional chargers and far more convenient. Simply put any ol' AA battery into the aluminum canister, plug in your cellphone using the appropriate adapter (available for all phones except Sanyo and Audiovox), and a chip inside the device amps the battery's 1.5 volts to a voltage powerful enough to charge and run the phone. A two-hour charge provides up to three hours of talk time. $25

For years, the phrase “PDA–phone combo” brought to mind clunky bricks that appealed to only the most connectivity-crazed early adopters. But the latest incarnations of these devices, now known by the more marketing-friendly tag “smartphone,” are finally fit for the rest of us.

So why do you want one?

Beyond the obvious calling capabilities, smartphones keep your calendar and address book close at hand (and ever more easily synced with your PC), provide access to e-mail and the Web,