Create multiple users with the same email address
When testing different user roles you usually want to create multiple user account each with a specific user role. The problem is that Drupal doesn't allow multiple users with the same email address. This can be a real hassle if you want to test more than 3 user roles. You can switch the role of the same user every time you're testing. Or you can use multiple email addresses. Impossible if you want to test 5+ user roles, because who in their right mind has more than 5 email addresses.
I've discovered a very neat trick which doesn't have anything to do with Drupal, but is still very useful. As far as I know this trick can only be used with Gmail or a e-mail address which is linked to Google Apps.
When creating a user in Drupal fill in the email address as follows: 'email+random_value@gmail.com'. For example your email address is 'johndoe@gmail.com'. You can append anything after 'johndoe' with a '+' sign and you will still receive the emails send to the 'johndoe+random_value@gmail.com'. Below an example the way I use it.
Editor role: johndoe+editor@gmail.com Site admin role: johndoe+siteadmin@gmail.comAdministrator role: johndoe+administrator@gmail.com
You can even use multiple '+' signs. Such as:
Editor and site admin role: johndoe+editor+sitedamin@gmail.com
This little trick saved me a lot of hassle. I've only tested it with Gmail and email addresses linked with Google Apps. Let me know if this tip was as timesaving for you as it was for me. Also let me know if this work with other email addresses such as Yahoo or Outlook.