Hohmann, Luke. Innovation games: creating breakthrough products through collaborative play. Pearson Education, 2006.
This book contains some great and handy tools for moderating groups, getting prioritations and achieving decisions. Some methods are very close to what agile practitioners use to moderate retrospectives (e.g., speedboat / sailboat). Others are great to achieve agreements in large groups (e.g., buy a feature). In any case, in a leadership roles, it is good to have some of them handy.
I will also link to a video in the media secion.