Limit your incoming spam!
Spamasaurus Rex is an effort to try and limit the amount of unsollicited mail you receive on your primary email address:
Often, creating an account on a website requires providing your email address; with Spamasaurus Rex you can automatically create a unique alias for use on such a website. You can then define rules in your mail client specific to these aliasses: for instance move mails to a folder or even instantly delete them.