San Francisco-based Nomad has unveiled the NomadPlus, a combination iPhone USB wall plug and rechargeable battery in one. The NomadPlus is unique in that it turns your existing iPhone USB charger into a portable battery pack. Just slide the charger into the 1,500mAh external battery, and as your iPhone charges, so too does the lithium-ion pack. The device -- measuring 2.75” x 1.33” x 1.10” and weighing only 2.1 ounces -- holds enough juice to charge a dead iPhone up to 70%. If you have $39 to spare, you can pre-order the NomadPlus now, directly from Nomad. Expect a late November delivery.