"I travel with a crystal ball," Rebecca Ryan jokes. As a futurist, she does a lot of travelling--and a lot of predicting. Of course, she uses data rather than mystic arts--she says she's informed by trends in five areas: society, technology, economy, environment, and politics. Lately, she's visited the Scenic City, and she's coming back next week. It's part of the Chattanooga Chamber of Commerce's visioning process, tentatively titled "A Vision for Economic Prosperity."