Nearly one-third of U.S. mobile phone users plan to upgrade their handsets within a year to get new features such as voice recognition, text messaging and downloadable ring tones, according to a study released on Monday.

A joint study by wireless research firm Telephia Inc. and market research firm Harris Interactive Inc. found that 31 percent of current wireless subscribers aged 18 and older plan to buy a new handset within a year, up from 27 percent a year ago. More here.