The only junk calls I ever get, between the Do Not Call registry and having an unlisted number, are from my insurance company. And I just hang up on them. I don't even bother to say "Not Interested." If somebody walked up to me on the street and tried to sell me something I'd just walk away. Same with the phone, I see no obligation to be courteous or tolerant. The only calls that bug me are from my mother. And god help me if I hang up on her.