On the NETTUTS.com site, a new tutorial has been posted about implementing a system to validate new members/signups for your site via their email.

Have you ever created an account with a website, and were required to check your email and click through a verification link sent by the company in order to activate it? Doing so highly reduces the number of spam accounts. In this lesson, we'll learn how to do this very thing!

The system takes a user's information via the signup page (username and email address), does some checking on the input, inserts the information into a backend MySQL database and sends a validation email to the user's address. The email contains a custom link the user then clicks on that confirms them as a validated account.