for a self-guided adventure in brainstorming, i would recommend the following (admittedly, it should be applicable to groups as well as solo tours). i have never understood why this books isnt on more book lists nor required to be in everyones shelves.
perhaps it is simply too clear for audiences demanding controversy.
The Universal Traveller
A soft systems guide to creativity, problem-solving, and thd process of reaching goals.
by Don Koberg, Jim Bagnall http://preview.tinyurl.com/5lu985