I thought this was a very good description from Accelerator (part of Bresslergroup) of the ideal brainstorming process and an interesting project. I do think brainstorming can still be effective, however, it is not something that just magically happens. Planning is key. This includes proper framing of the problem, key constraints and letting people think about it separately on their own ahead of time. Everyone comes prepared with ideas ahead of time and all ideas are presented whether the person behind them is the "loudest in the room" or not. I also enjoy the rule about not criticizing an idea unless you can come up with a better one.