iToner 1.0.3 in beta testing: works with iPhone 1.1.1 (in our tests)
Ambrosia Software is now beta testing iToner 1.0.3, a new release of the software for transferring any MP3 or AAC track to the iPhone as a ringtone that works with iPhone software/firmware 1.1.1. Version 1.0.2 of the application was rendered non-functional by the 1.1.1 release, but the Ambrosia development team has discovered a means for again putting and playing independent ringtones on updated devices.
While Ambrosia cautions that iToner 1.0.3 (currently in private beta) still needs to be fully tested in order to ensure proper operation, we transferred several tracks to our 1.1.1 iPhone which played back properly when selected from within the "Sounds" pane of the "Settings" application.
iToner makes use Apple's APIs to access the user area of the phone, allowing the placement of ringtones. Older versions of the program could still perform the same basic transfer routine under iPhone software/firmware 1.1.1. The reason the tool hadn't been released in a 1.1.1-compatible version is because of a mysterious new signing mechanism used for ringtones that allows some tracks to play, and disallows others, with no discernible basis for discrimination. Apparently, Ambrosia found a workaround.
iToner is priced at $15. The current 1.0.2 release works with iPhone software/firmware 1.0.2, and the iPhone software/firmware 1.1.1-compatible release should be forthcoming shortly.

The update for Leopard is only a few weeks away, if they dont know what to react to, we should be free and clear to use all the J-Apps through the new year -- or until another update comes out, which won't be that soon, i'd guess...