newegg.com offers the Energizer Protective Case with Built-in Battery for Apple iPhone 3G / 3GS
, model no. AP1500, for $12.99
. With free shipping
, that's $2 under our August mention (which also included a usable case, see below) and the lowest total price we could find by $7. It's also the least expensive iPhone case we've seen with a built-in extra battery. This protective case features a built-in battery and has an LED battery life indicator light. It comes with a USB charging cable and provides up to four extra hours of talk time.
Have a friend with an iPhone 4? newegg.com includes a free X Games Platinum Snap-on Faceplate for iPhone 4 with this item. (It won't fit the iPhone 3G.)
Need it for Christmas? Order by 3:30 pm ET today (December 21) and choose UPS Guaranteed 3-Day Service for $5.99.