CargeCard iPhone 4/5 & Micro USB Chargers: $25 Running out of battery on your cell phone sucks and chances are you didn't happen to bring your extra charger with you. Tuck one of these credit card size chargers in your wallet and you'll never worry about finding a charger. Now you'll just need to find a USB port to plug into, but those are plentiful if you look around (computers, televisions, and more).
SanDisk Retractable Slim Card Reader w/4 Storage Slots: $9.95 This credit card memory card reader fits perfectly in your wallet. It can read microSD, microSDHC, and M2 cards and comes with a retractable USB plug.
American Express 16GB Credit Card Flash Drive: $16.99 $1 per GB may be a lot until you realize that it's a credit card size flash drive that fits in your wallet and you don't have to bother wondering if you grabbed your USB drive when you need that file on the go. With the American Express logo though don't accidentally try to grab this card at the grocery store!
CustomUSB Wallet Cards: Customized, bulk pricing Customize your own wallet flash drive as a perfect marketing or company gift. MORE CREDIT CARD USB PERIPHERALS ON APARTMENT THERAPY • ClickFree Traveler: The Credit Card Backup Solution • Verbatim Wallet Drive (Daily Find) • USB Medical Card: A Better-Safe-Than-Sorry Investment