The Yellow Jacket is an iPhone case currently seeking funding on Indie Gogo. In addition to shielding your phone from the elements, it also packs a walloping 650,000-volt punch when needed. When you're not using that feature, it also functions as an external battery that provides up to 20 hours of additional talk time.
It's the brainchild of Seth Froom, who came up with the idea after being robbed in his home. Check out the pitch video below, which features a surreal reenactment of the incident.