United Airlines has announced the launch of iPod and iPhone connectivity for its in-flight entertainment system, becoming the first U.S. carrier to offer such features. United’s system, developed by Panasonic Avionics Corporation, allows users to attach an iPod or iPhone via a 30-pin connector and view content on a 15.4-inch personal monitor, while charging the device at the same time. The system will debut later today on United flight #936…