The Associated Press reports today that about 13 million people signed up for the Federal Trade Commission's Do Not Call list in its first four days of operation. (About 3 million have yet to confirm their registrations.) That's 13 million of an estimated 166 million residential phone numbers in the U.S., or about eight percent of all eligible phone numbers. The FTC expects 60 million registrations -- over a third of residential phone numbers -- in the first year.