I'm looking for a spare battery for my 3G (something similar to the RichardSolo) that has both a male and female dock connector (plug the male into the bottom of the iphone and plug the iphone charger into the female dock connector in the bottom of the spare battery). Does such a product exist? I've searched around and all I seem to find are spare batteries that charge via a mini-usb connector. I want something that I can charge every night along with my iphone as it sits on my nightstand.