I took it myself (and Stephen is probably tracking my answers!) -- it's very cool and quickly teaches a good lesson in good vs. bad graphics and tables. You will be strongly discouraged after it to abuse color, 3D, etc.
If you got hooked, Stephen has a big bag of goodies for those who want to learn about creating good graphs and tables. He wrote a beautiful book called "show me the numbers"

His website's Library also included an abundance of useful articles.