An Android app is available at the Android Marketplace.
It allows one to choose a ringtone and download it directly into the phone, and then give one the option of setting it as a ringtone.
Every time that tone plays, through the action of someone calling the phone, it will send information to the website detailing where and when it has played.
You will be given the option to opt out of this – if you don’t want to give away location data you can disable this prior to downloading the app.
For more information please read The Map & Location section.