National Do Not Call registry...

If you're going to string them along, the best thing to do is sound excited at whatever they're offering, and ask them to hang on while you go get your wallet / purse so you can grab your credit card. They'll sit there waiting for HOURS for you to come back to the phone. Pick up the receiver 3 hours later ... "Oh, great, you're still there! I'm still looking for it. Hang on! ..."

Some call me Evil Incarnate. :-D