If you watched the Filip Polc footage from his urban DH descent you probably noticed some great camera angles. Here’s how they were captured:
http://www.pinkbike.com/news/Filip-Polc-Red-Bull-Valparaiso-Cerro-Abajo-Insane-helmet-cam-2013.html
The 'Copter Cam… I’m surprised Snider hadn’t thought of thought of that first.