Yesterday, we looked at two tactics for dissuading telemarketers from calling again: giving them a fake name so you can detect them next time, or hanging up without another word. If neither of those appeal, here's some more options.
Commenter Jack Cola offered up a link to his own collection of tactics for putting telemarketers off. The essence of his strategy is to make the telemarketer hang up rather than doing so yourself, using tricks such as pausing after each answer or pretending you can't hear them. For me, a simple slam-down still works the best, but it's always good to have extra tricks up your sleeve.