When I am on the computer and see calls with blocked or missing Call IDs, I let my fax software answer the phone. Even folks who don't understand TeleZapper, hardware that generates tones that indicate that a number is disconnected, understand fax and rarely call back. Before the No Call List went into effect, I disconnected my incomming phone line if I wanted to sleep, and let the phone company's call answering software answer the phone. If they were decent enough to leave a message, I might return their call - most telemarketers don't render this courtesy, though.

   Dave