Inc.com just released their annual valuation guide for 2009, which allows business owners to gauge the value of their, uh, business. At the center of this guide is an interactive "business valuation calculator" by Tommy McCall. I guess the best way to describe the graphic is Trendalyzer with some style and added functionality.
Each dot represents an industry and the position on the chart indicates whether the companies in that industry are priced high or low. Press the play button and watch how prices change between 2002 and now.
Finally, if you've got a business of your own, enter your own values to for a custom value estimate.