Quick question: Do I need a Lightning adapter?

Can't seem to find an answer to this.

This is a longshot, also I'm a big noob with consumer tech, but instead of buying a $29 adapter ($35AU for me) to connect my new iPhone 5 to older accessories - could I possibly use the lightening to USB cable, a short USB extender, then a USB to 30 pin cable?

Would this even pass power through to my phone, say in the rare case that I'm staying somewhere, or in a car, with an iPhone dock and no USB port to charge off? I know it's a pretty rare case...

Or does my excellent ridiculous solution also require a smart chip that tells my phone that everything is O K (and do complex 30pin to lightning conversion)?

Honestly I don't think I'll need an adapter very often, if at all, but I've got these things lying around and would love to save $35.

Thanks in advance for not taunting my naivety in the comments!