It looks like a USB charging cable swallowed a AA battery. What's inside is a lithium-ion battery with more capacity than built into any current iPhone or iPod. Using this cable, sync or charge your device while the internal cable battery charges. It will take about 3 hours to fully charge. Then when your device runs out of juice, plug in the cable and get power while you charge your device's battery.
I spoke with Alan Pocrass, the CEO of Xmultiple, and found that the information now circulating around the Internet is wrong. If you've already read something about the product, that information was based on a production prototype that will not be be built. The publicity picture is also inaccurate. The cable will work with iPhones, iPod touches and USB-charging iPods only, so earlier iPod owners (those that charge via Firewire) are out of luck.
Keep reading for more specifications...
Xmultiple produced 10,000 units and sold out in two weeks. A new shipment of 100,000 is due to arrive on August 25th and will at first be available from Xmultiple with the intention of later rolling it out to a number of vendors.
Three models of varied length and battery sizes will be available:
3 inches with a 2100 mAh battery for $19.15
6 inches with a 2300 mAh battery for $22.95
10 inches with a 2500 mAh battery for $25.95
There will also be a 42 inch one with a 2500 mAh battery which is the size that Apple ships.
[Earlier lengths listed in feet were incorrect; miscommunication with Xmultiple]
The only cable tested was 10" and it provided the following results:
4.5 hours of 3G talk
9 hours of 2G talk
up to 5.4 hours of Wi-Fi
270 hours of standby time
6 hours of video playback
The August 25th shipment will not contain an inline flash card as commonly reported. That configuration is planned but will not be available until the fourth quarter along with a proposed retractable cable.