Here is an application that is available on android market for quite some time. I just never tried it primarily because my ADP1 just ran out of space for installing additional application. The application is called Ringdroid. The application can read any MP3 stored on your phone or you can record any sound and then it allows you to define the boundaries of what you want to set as ring tone.
Works pretty well and I found it useful. Use the QR Code on the right to jump to this application in the market.