ProClip has announced its new Holder with Tilt Swivel and Pass-Through Connector for the iPhone 3G. Designed for use with the company’s vehicle mounts, the holder offers a pass-through connector on the bottom for attachment of dock-connecting cables, creating a docking station for the iPhone 3G and removing the need to plug and unplug the cable each time it’s connected. The holder can also swivel 360 degrees and tilt 15 degrees in any…