So I just downloaded the Antares Autotune Evo 5 trail. This program is, to my knowledge, the industry standard Autotune. It's a very simple program to use and is compatible with most common producing programs.
It's power is amazing. It's basically a piano roll where you just put the notes you want to hit and it corrects your pitch and viola! As long as your settings are properly adjusted (the hardest part) and your original track isn't WAY off, you have yourself a decent vocal track
An example of Autotune at work, a cover of Jay Sean - Down:
http://www.newgrounds.com/audio/listen/307417
Thats me singing (I am fully aware of the suckage, thank you). Both tracks have the exact same original vocals and exact same beat. I exported the original and then autotuned it and exported it again.
The autotune track also has some Delay, Compression and Equalization added to it as well to make it sound as good as possible.
That was done in about 10 minutes and I've been using the program for maybe 45 (Settings took a while)