The device is 0.1 inches (2.54mm) thick - about three times as thick as an everyday credit card - so it should not fatten up your wallet too much. The 3.25 x 2 inch (8.3 x 5.1 cm) body (including the connector) is constructed from ABS plastic and the fold out USB part is made from flexible thermoplastic elastomer that is designed to bend and prevent it from snapping off while open.
In use, ChargeCard works like a standard phone cable, but the compromise for its portability is that it's much shorter. Obviously it's not designed for charging your phone and using it from across the room, but in most situations it can get the job done.
Noah Dentzel and Adam Miller, the creators of the ChargeCard, designed it so it can work with bulky cases such as an OtterBox (but unfortunately LifeProof case owners will have to remove the phone from the case).
ChargeCard has passed its funding goal on crowd-funding site Kickstarter and the first batch will be available in black, white and teal on brown for US$20. The company expects to deliver the iPhone version to backers in September and a Micro USB version (for Android or BlackBerry) is slated for a November release. The developers are also planning to cater for the new connector expected on the iPhone 5.
Dentzel and Miller take us through the device in the Kickstarter promo video below.