Every time you hear a tune where the vocalist's voice "pops" mechanically from one discrete pitch to another, like running your finger up a keyboard. When it first came out, it was used very delicately, on just one or two phases, maybe, to clean up an otherwise keeper take. Now, people use it like they are actually *proud* of it- with every single phrase in the lead vocal smashed to the max, and this little robotic/vocoder-sounding voice is all that's left. You plug your guitar into the Pod, and you plug your vocalist into the autotune box. It's How It's Done. Shit, even in country and commercials now...
Even when it's used subtly, you get this "snap" to pitch thing that just isn't right: vocalists just don't scoop pitches that way. Autotune is definitely the sound of the decade for pop music. I'm _extremely_ glad that I don't do pop (and never have), and you'll never see an autotune box or plugin in my room.
To quote my gray-haired mammy: "Gag a maggot on a shitwagon". Sorry, folks, but it is not for me.