> For Mother's Day I got my mom a little device that plugs into your phone line. Whenever you hear a telemarketer, you press its button and hang up. This device plays a polite, recorded message asking the telemarketer to take your phone number off of their list. It is really fun and my mom swears her number of telemarketer calls has been cut in half.

that's not what you want to tell them. You want to tell them to put you ON their do-not-call list. The only "lists" telemarketers maintain are restriction lists- - -do-not-call, do-not-share-information, etc. If you tell them to take you OFF their list, they'll gleefully do so because you have just given them legal permission to call you and to sell your number to every other telemarketer who wants to call you.