Guerrilla Mail gives you a disposable email address. There is no need to register, simply visit Guerrilla Mail and a random address will be given. You can also choose your own address.
You can give your email address to whoever you do not trust. You can view the email on Guerrilla Mail, click on any confirmation link, then delete it. Any future spam sent to the disposable email will be zapped by Guerrilla Mail, never reaching your mail box, keeping your mail box safe and clean.