OK, it's not a working iPhone 5. But still, it's the same size as an iPhone 5, and, it's handcrafted out of a piece of steel.
Recently, a do-it-yourself type took a 140mm long, 60mm wide, and 6mm thick steel plate, and he turned it into an iPhone 5 replica. The gentleman documented the entire process on a Chinese social networking site (via MIC).
To achieve the grey back, the guy used chemical water instead of a dye. Dyes fade, but chemicals are forever.
After polishing it, he drew an Apple logo in pencil and put paper touch screen on the front. And voilà, a very heavy iPhone 5 replica to impress friends and family.