Thanks Yasor, but I still don't know what auto tune is.
---------- Post added 09.09.2012 at 15:39 ----------
Auto-Tune is an audio processor created by Antares Audio Technologies, which uses proprietary software[2] to alter pitch in vocal and instrumental recording and performances. It was originally intended to disguise or correct off-key inaccuracies, allowing vocal tracks to be perfectly tuned despite originally being slightly off-key.
Sounds pretty neat.