Amy Shuen inspired me to prepare a spreadsheet for estimating the value created by my talks. (You can open the spreadsheet in OpenOffice.org or Lotus Symphony, both free office suites.) She’ll be including some of the numbers in tomorrow’s IBM Web 2.0 for Business community call on ROI of Web 2.0 at Work. I thought I’d make the numbers a little easier to grasp, so I spent an hour and a half making this:

Full-size images at public-speaking-1.png and public-speaking-2.png.