CasterSoundboard - A soundboard for hot-keying and playing back sounds. (For podcasting)
Celemony Melodyne - Celemony Melodyne is the perfect quick and easy tool for all your tuning needs.
JN Soundboard - An open-source hotkey soundboard program
Revoice Pro - Revoice Pro is an audio plugin used for vocal tuning, time correction and ADR.
Soundplant - Play sound files with the computer keyboard
CrispyTuner - Fully featured vocal tuning suite.