If you're looking for a very light portable charger to boost your phone battery over a long and busy day, check out the credit-card-sized myCharge RazorMini portable smartphone charger.
myCharge has a nice line of chargers, including small, rugged, and hub models (see earlier posts) -- and miniaturized down to the RazorMini, which is just thick enough to include a USB port to plug in your device.
The RazorMini has a 1650mAh battery with 1.0A output, to charge smartphones for up to an estimated 15 extra hours of power. It includes the myCharge fast-charging and rapid-recharging technologies, and can hold the charge for up to one year.
The RazorMini is clad in anodized aluminum with a minimalistic design, with only the USB charging port, a micro-USB port for recharging, and 4 LED status lights. There's no buttons -- just shake it to to view the battery level.
It really is the size of a credit card, and around the thickness of four cards (3.5 x 2.1 x 0.3 in. and 2.2 oz.), and does fit in the credit card pocket in my wallet. It's available for around $29.
Find the myCharge RazorMini Charger
on Amazon.com