I use this one,When telemarketers call(on the cell phone) most of them know I am a paint contractor so I say that I am on a large ladder and then they start their pitch when I think they are about done I remind them about that large ladder and I pretend to fall and holler, "OH CRA------" and drop the phone, and they hear dead silence.
Usually, I'm removed from their list, but a few have called back to see if I was okay, but we leave 'em hanging and don't answer the phone.
(No cellphones are harmed during this exercise.)