This is a must see talk from Ted. The speaker, Tim Brown is the CEO of the "innovation and design" firm Ideo, and his talk is about the powerful relationship between creative thinking and play.
At least to me, the whole thing about how playing can help creativity to thrive is not new at all but the reason I liked his speech is because he also talks about the need for some "rules", something that tends to be forgotten too often when it comes to creative brainstorming.
It is a 20' video but worth the time (click on either "player" line below to see the video):
Those that know me, know that I am not exactly a lover of rules. Nevertheless I do see the need for some basics rules when it comes to creative thinking (specially when it is done as a team) and Tim's talk, stating the differences between creative exploration and creative playing highlights the reasons to have some basic rules to brainstorm (or play) as well as the problems that can be avoided by playing by the rules.
Not a believer in rules? Feel free to disagree!