Forget brainstorming. Innovation is a group activity accessible when we go off script.
In workshops and seminars, improv consultants pull stodgy executives to their feet, creating novel situations to which they must react, encouraging them to move their bodies, jump, say wild things, clap or sing or dance, play with toys, sit on desks, crawl on the floor and generally provide crazy-seeming new points of view. Tension melts away. Competition takes a back seat. And new ideas miraculously start to flow.
Like Jane McGonigal's idea of happiness, it seems to me that innovation better thought of as a accessible and beneficial activity or state of mind. It takes action.