John Walkenbach is a leading authority on spreadsheet software and principal of J-Walk and Associates Inc., a small Tucson-based consulting firm that specializes in spreadsheet application development. John is the author of about 50 spreadsheet books and has written more than 300 articles and reviews for a variety of publications, including PC World, InfoWorld, PC Magazine, Windows, and PC/Computing. He also maintains a popular Web site (The Spreadsheet Page,
www.j-walk.com/ss) and is the developer of the Power Utility Pak, an award-winning add-in for Microsoft Excel. John graduated from the University of Missouri and earned a master's and Ph.D. degree from the University of Montana.