I found the following in Florida Today Newspaper. Verra interesting ...!
I've been hearing about an alternative to the TeleZapper, the device that tells telemarketers' automatic dialers that your phone number is no good. It turns out that several Web sites carry the secret, for free: the three-tone combination that your phone company uses when you dial a number that is disconnected.
The trick is to record those tones at the beginning of your message on your answering machine. When you let your answering machine answer the phone, the automatic dialer should register your number as a bad one and take you off the company's list.
Try searching for "free telezapper" on your search engine, or, for your convenience, here's a site where you can download the tones:
www.thefontman.com/telemarketers.htm
Of course, it will be easier if your machine is near your computer, so you can record the tones with a minimum of fuss. You can figure it out.
Follow up the tones with an actual message so your mom doesn't think you've moved without leaving a forwarding number. Unless, of course, that's what you're trying to do.