Albeit an iPhone-sized one. But strap a few of them together and, by the looks of this video, you'd have a fairly cheap makeshift bullet-proof vest at your disposal.
The Proporta Carbon Fibre Leather Case for iPhone 5S and iPhone 5C survived a shotgun spray from Uncle Barry at 20 paces -- a shot that would be lethal at even 25 paces. Priced at £44.95, it's not the cheapest case out there by any means. But given it seems to be aimed at bankrobbers, I'm sure they've got a few quid to spare. [Proporta]