Das Blau has introduced its new Slipper Case for the iPhone. The Slipper is a slim, sleeve-style case made from a combination of lambskin and fabric and featuring suede lining, a front pocket for holding cards, cash, or earphones, a ratcheting belt clip, and shock-absorbent padding. The Das Blau Slipper Case is available now for pre-order in red lambskin with a gray checkered fabric, or in brown lambskin with an olive-dark blue striped fabric, will…