If the concept behind Iomega's new SuperHero ($70) doesn't initially make complete sense to you, we understand: this new accessory is clearly being pitched at a very specific though potentially large fraction of the total iPhone userbase. SuperHero is a plastic and metal dock with a total of three connectors: an iPhone and iPod touch-ready Dock Connector at the top, a power port in the back, and an SD Card slot alongside the power port. Iomega packages…