A Response to Friendly Spam (Hat Tip: Greg/New Jersey).
I have many friends who are not too technical. When they get an email saying "forward this to as many people as possible and we'll pay you for each one" they believe it. I no longer bother to tell them that there is no way for Microsoft to track their emails. However, a friend sent me the perfect response. Next time you get one of these pieces of friendly spam, send this URL to the culprit. It is a wonderful way to stop this practice while keeping your friends.