Newer models of cellphones coming on the market today are virtually mobile computing stations. They allow real or true audio like mp3s, wav, and wma files to be used as ringtones for your mobile phone. To  download mp3 ringtones for cellulars  safely usually entails gong on to your provider’s site, selecting a file, and paying a fee. There are other online sources but many of these harbor viruses that can render your phone useless. You can occasionally download mp3 ringtones for cellulars through a computer via a USB, IR or Bluetooth connection.