The site is SpamMotel.com and it requires only a small download to work. When you click on the SpamMotel icon on your desktop, a box pops up that lets you type a reminder note to remind you why and to whom the email address is being given. SpamMotel then records this reminder note, and logs the date and time. It creates a special email address for you to give out instead of your real one. Simply paste this special address into whatever field requires it. You're all set; you don't need to do anything else.
Whenever the sender (or spammer) sends you email, it is forwarded to your regular e-mail address along with your reminder note and other useful information, which appears at the top of the e-mail. They tell you when the special address was created. How many e-mails you've received from that sender. The date that the sender last sent you e-mail.
If you're getting spam, it's then easy to temporarily stop or permanently delete that address - effectively stopping the spam.