http://www.youtube.com/watch?v=evG3fGJrwRE
And I'm working on another one that we did with multiple cameras and some crowd-sourced clips from YouTube.Though, in these cases, we recorded the entire concert. Even when I record just a bunch of little clips, I'll get a couple dozen to a few hundred views. And I certainly enjoy watching clips that other people upload now and then.
As to whether there is a startup that could do for me anything in this regard that YouTube and iMovie/Final Cut can't, I would tend to doubt it. Other than perhaps making it easier to piece together more of a concert from crowd-sourced clips.