There are a couple ways to swap that horrible default chirping noise for something more pleasant without shelling out $3 a tone to your carrier. The easiest way is to use the Web service Mobile 17. Sign up for a free account, enter your phone model and provider, and upload your MP3 or M4A file. Choose the point in the song at which you want the ring to start and how long a clip you´d like. In a few minutes, Mobile 17 will send a file in the proper format to your phone by e-mail or text message (you can then save the attachment as a ringtone).