Twitter is all the rage, but apparently not worth a fee, according to a new study from USC's Annenberg School for Communication and Journalism that found none of its participants would fork over any money for the 140-character service.

" ... exactly 0 (zero!) percent of the the 2010 Digital Future Report's 1,981 participants said they would consider paying for the popular - and to this point, free -- social messaging service," TheWrap.com reports on the survey. “About half of those surveyed in 2009 said they use free 'micro-blogs,' including Twitter Facebook's status update. But for Twitter specifically, they aren't willing to pay.

”According to Jeffrey Cole, the USC project's director, such an 'extreme' finding 'underscores the difficulty of getting Internet users to pay for anything that they already receive for free.'"