The torch has arrived, the athletes have settled into the village, and the opening ceremony has commenced. We're just as excited for the Summer Olympics as you are, but there's a lot more taking place besides the on-field events. From the velodrome to the entire Olympic Park, this year's Games are being touted as the greenest in history and offer some of the finest efficient architecture and innovations yet. To coincide with the lighting of the flame, here are five of the best sports and stadia-related ideas from Planet Forward. On your mark, get set...GO!