RingSynth is a powerful, user-friendly music sequencer designed to create ringtones. Build and create your own ringtones using instruments such as a electric guitar, drums, saxophone, bass guitar, etc.. You can also make your own instrument by recording yourself or anything you can get your hands on. When you are done export your song and upload it to your phone using itunes.
Special thanks to Zeta Centauri, Inc. for some great instrument samples, you can check them out at http://freewavesamples.com/