A handheld electronic device for use at a venue hosting a live sporting event, having a receiver for receiving a wireless RF transmission conveying a plurality of video streams derived from video cameras filming the live sporting event, a display and a user interface for selecting a video stream among...http://www.google.com.hk/patents/US20070018952?utm_source=gb-gplus-share專利 US20070018952 - System and Methods for Enhancing the Experience of Spectators Attending a Live Sporting Event, with Content Manipulation Functions
