I am the only person that doesn't actually know what a "ringback" is. I've heard the term time and time again, most recently in an article by the trusted and informative Mi2N, and had to Google it.
And apparently, there are people who are smarter than I am who not only know what a ringback is but have figured out how to get personalized ones onto their phones. (They probably also know how to change their phones' screen savers. I do not.)
Ringback tones are on track to become the most attractive mobile content category by 2012, according to new market research from MultiMedia Intelligence. With worldwide revenue nearly tripling to $4.7 Billion, ringback tones will fall just short of mobile gaming revenue in capturing the largest share of the mobile premium content market (not including mobile video and mobile TV).