Ok so Auto-Tune (for those not in the know) is a magic device that makes ppl sing better. It was created by a guy who was working on a seismic exploration tool. Cher hit it big thanks to Auto-Tune and her fantastic jam Believe. T-Pain (whoever that is) is only successful because of it. Most recently Kanye West ripped off T-Pain's schtick and released a whole album of Auto-Tune R/B jamz.
All that... fairly pedestrian usage. Auto-Tune has now been used to make the news interesting. It is totally sweet.