Forgive my rambling here, but I am having a lazy afternoon and wanted to kill some time so...
haiiro said:
I bought World Builder, but I haven't used it much at all (at least, not yet).
I felt that the WB reference is best used during preparation of an adventure, especially a written module intended for publication. What seems ironic for myself is, although I've been involved with RPGs for 21 years, I haven't actually been the Game Master of a campaign since 2001. In the past three years I've run very few adventures, unless they were "one-shots", improvised on the fly (such is life for the older gamers, right folks?) Thus, my poor World Builder has remained on my shelf, without much use. Bah.
When I picked it up, my idea was to use it for two things: fleshing out cities (since it includes info on different jobs, types of people, etc.), and expanding my descriptions of minor game elements (with the big lists of herbs, etc.). This sounded good, but in practical terms I don't generally think to make use of it.
I would like to believe the book is perfect for the tasks you mention. Perhaps GMs who always improvise their adventures "on the fly", spinning their tales in a fast and furious pace---with more emphasis on political or social interaction---would make little use of the WB descriptionary. However, I imagine the book being quite handy for detail-oriented GMs wishing to flesh out the contents and descriptions of certain key campaign areas, large and small. I'm talking about the sort of detail which is common in dungeon crawls, or with complex city adventures which place some importance on the whereabouts of certain buildings and hideouts. I also hoped fantasy authors would pick it up as a tool to help them envision the settings of their principle protagonists; afterall, characters in a novel must interact with "stuff" to help set the stage. Oh, and I apologize to anyone who hates the word "stuff". I know you're out there.
I own a fair amount of d20 books that fall into this category, and I've found in the past that they often lurk on my shelf until the perfect situation comes along to use them. World Builder feels like that kind of book to me.
I would especially like to suggest using the World Builder for writing adventure modules intended for publication. In fact, I suggested the idea of the World Builder to Gary in reaction to the difficulties involved with writing large adventure modules (as yet unpublished) for his Lejendary Adventure game. I wondered how to make every location in my adventure unique. The larger details were easy to paint in broad strokes, but smaller details were vexing to me. Perhaps I went overboard, but I had researched medieval buildings and architecture for the sake of describing every building in the principle featured city. These descriptions were merely one paragraph each, intended to be read aloud by the GM upon first visitation of the site by the PCs. That level of detail was easy to achieve for the first Inn or Temple I described in my adventure modules, but I quickly found myself wishing for a "menu" of descriptive elements, so I could make each location unique, at least in suitable ways (without resorting to a hodgepodge of architectural styles from different historical periods). Many modules, I felt, made either the mistake of too much description, boring us with large chunks of prose, or just eschewed description altogether while remaining wholly generic (which is, I admit, not always a bad thing).
So my focus in writing has been on "brainstorming aids" rather than on writing how-to guides. That's why my next book (one I authored alone with Gygax as my editor), is on brainstorming plots rather than an entire book of ready-made plots (although it does contain plenty of them as well). I hope that GMs will be able to derive from that book a bazillion adventures on their own. And perhaps those adventures would need fleshing out with physical descriptions for the encounter locations...perhaps using the WB? I can only hope. At least that was my mad plan.

I figured that a "brainstorming aid" for adventure plot construction would be better than a book dictating whole plotlines, because the typical D&D GM makes up his own adventures anyway. The last book like that I'd seen was written by Aaron Allston in the last eighties or early ninties...what was it's name? Dungeon Master's Design kit?
Now if only I could get a game going...