Kakophone: DIY Ringtone.

The Kakophone is an online ringtone generator for your cell phone (mobile phone, for the rest of the world).

Generating your own music is quite simple: just a few clicks (of mysterious buttons, although I suspect you’ll get the hang of it if you spend some time there).

You can then download (MIDI format) or have the resulting ringtone sent to your phone. Corrected Link – via Ursi’s Blog