Hey there, RadioNerd. Glad you liked the article. Let's figure out what went wrong, eh? First things first - the article does mention a command to try. The very last code example on page 2 lists the HTML source of a SSI document, which would include the contents of the CGI script we tested on page 1.
As for the SSI not working, there could be a couple of reasons - did you restart the Apache webserver? Did you correctly uncomment the AddType and AddHandler lines in the config file (code snippet 1, page 2)? Did you correctly add Includes to the right directory (code snippet 2, page 2)?