Posted on 
Aug 31, 2007 05:25 pm Sorry for not getting at this sooner.
Part of the effect is done with simple EQ and not using a pop shield on the mic. When it gets into the funky effect you are talking about that is probably an Antares auto tune being cranked up to the max. It is the same effect done on the tune Cher did back some years.
You can get a similar effect using a vocoder as well. That would require a midi controller to use though, or step writting the data that the vocoder will use to control the pitch shift.
The Autotune is available as either hardware or DSP pluggin. I would opt for the hardware myself.