Auto-Tune!

Celemony Melodyne is the perfect quick and easy tool for all your tuning needs. Great for editing pitches of instrument and vocal recordings (auto-tuning your voice) and even sounding like a robot!30-day unlimited trial.

"Pop music in a can!"

With GSnap you can get an auto-tune effect. It can be used subtly to correct the pitch of a vocal, or, with more extreme settings, to create a robot-voice effect. It requires a monophonic input signal to operate.

Voxal is a state of the art voice changer software to edit voice recordings. Voxal can be used to enhance any application or game that uses a microphone. Add effects to a recording as well as intercept and add change audio as it comes into your microphone for voice changing on the fly. Change your voice in several different ways by adding effcts like pitch, echo, and much more. Effects can be used together to provide numerous combinations. Voxal works behind the scenes so you won't need to change any settings in your other programs. »

Graillon is a Vocal Live Changer that brings a world of possibilities right into your DAW, with carefully designed features:

Revoice Pro is used worldwide by top audio professionals for the fastest, easiest and best sounding adjustment and alignment of vocals, instruments and ADR as well as double track generation.

A Pitch Correction LV2 plugin derived from AutotalentThis plugin should work basically the same as Autotalent except:

NewTone (editor) is a pitch-correction and time manipulation editor. Slice, correct, edit vocals, instrumentals and other recordings.

This changes your voice from everyday ordinally to robotically Ke$ha/T-Pain-like. Lots of artists use Auto-Tune for example: T-Pain (duh), Lady Gaga, Ke$ha (it's obvious), Victoria Justice (obvious, sometimes), and more. This is a great app to be using.

Specimen is an open source, MIDI controllable audio sampler for Linux. Features include: