The application in this chapter is a good example of several techniques that you might need in your programming tasks. First, there's an interesting use of GDI+ as the certificate is tiled and drawn. Second, creating a list of files in a directory is something that is done fairly frequently. Third is the use of the MailMessage class to send out e-mails.
You can easily enhance this application by adding additional properties such as font size and style. You can use the Certificate class to automatically create a certificate for online contests that you might be holding and then you can e-mail the link. If you give yourself enough time, you'll come up with lots of ways to use and extend this application.