No Jailbreaking Required. No hacking!
Just ringtones. On your phone.
Your phone will be (at least with version 1.0.2) upgradable, syncs, etc. No need to restore for firmware update!
What we are doing is adding a directory called /var/root/media/iTunes_Control/Ringtones/ and placing a file called Ringtones.plist to /var/root/media/iTunes_Control/iTunes/
These are most likely (and curiously) the future placement of Ringtones via iTunes?? (Wild speculation).
http://ringtonesapp.googlecode.com/files/Ringtones_1.1.dmg
Source code will be available shortly.