Note that how much hard tune effect you get depends a lot on how you sing. It is harder for me to get that effect on my voice than on others. (I don't want the effect in the music I do, but I have experimented with V-Vocal, Melodyne, and TC Helicon VoiceWorks Plus out of curiosity.)
Trivia question: I remember a male rock group using this effect before Cher but I cannot remember who it was. Anyone recall?