Marware is shipping the C.E.O. Premiere for the iPhone 4 (http://www.marware.com/products/iPhone-4/C-E-O-Premiere-for-iPhone-4). The US$34.99 holster case sports a black leather with white accent design and an attached belt clip so you can slip the case into a pocket, purse, or briefcase if the clip isn’t needed.
A push-through opening at the bottom of the case helps with removing the iPhone quickly. A Velcro closure keeps your iPhone securely in the case, and purportedly won’t cause antenna or GPS interference like magnet cases. The leather used is RoHS compliant (Restriction of Hazardous Substances) and better for the environment.