A few people have asked me about the subtitle to Finding Oz, wondering whether it would be more accurate to say that L. Frank Baum "created" the great American story rather than "discovered" it. The question gets to the heart of invention and imagination.

Baum himself noted that he did not actively set out to create The Wizard of Oz, even though in a sense you could say he was searching for it his whole life. "It was pure inspiration," he once said. "It came to me right out of the blue. I think that sometimes the Great Author has a message to get across, and He has to use the instrument at hand. I happened to be that medium."

His sudden discovery of a story that had been brewing for many years is consistent with what many great artists have related in describing moments of inspiration.

For instance, Paul Simon has said that his most inspired songs were not actively created. "If I make it up, knowing where it's going, it's not as much fun," he tells Paul Zollo in Songwriters on Songwriting (2003). "It may be just as good, but it's more fun to discover it ... in the underground river of the subconscious ... it comes to the surface occasionally and you have to capture it when it happens." Then he switches metaphors. "It comes through you, but you don't possess it. You can't control it or dictate it. You're just waiting ... waiting for the show to begin."

Stephen King, in his memoir On Writing (2000), reveals something similar about his story generation process. "My basic belief about the making of stories is that they pretty much make themselves," King writes. "Stories are found things, like fossils in the ground ... stories are relics, part of an undiscovered, pre-existing world. The writer's job is to use the tools in his or her toolbox to get as much of each one out of the ground as intact as possible."

So which is it? A divine message? A signal from space? A river of dreams? A buried treasure? It's whatever works. But if I had to pick one word for the process, I would say 'discover' fits a bit better than 'create.'

Now that James Cameron has surpassed himself with a new all-time global box office champ, a lot of people are calling Avatar "the most popular movie of all time." At first glance, it seems so.

But seriously, it's not even close. Not by a long-shot. Adjusted for inflation, it currently ranks #25, about even with Grease, according to boxofficemojo, with 1939's Gone With the Wind still fluttering at the top. But in terms of total number of viewers, that other film from 1939 takes the cake.

CBS calculated in 1983 that a billion people worldwide had seen The Wizard of Oz. The Library of Congress has called Oz the most-seen movie of all time. Estimates now range from Two to Three Billion viewers, including old-style network TV and home video.

By comparison, about 200 Million people have seen Avatar so far (if average ticket prices are $10). So it's the Munchkins over the Na'vi, as the film based on L. Frank Baum's novel seems fairly secure as the reigning champ of our collective consciousness.

In related news, Cameron tells NPR's Terry Gross that The Wizard of Oz is hands down his favorite film.

'Twas a Great & Powerful "Oz-tober" weekend in Chicago, where a tour bus morphed into a time machine, whirling us back to the days of L. Frank Baum & the origins of Oz.

The sold-out Oz Bus Tour featured a journey to the only remaining fairgrounds building from the 1893 Columbian Expo, the place that inspired Baum's conception of the Emerald City.