However, users reported that after installing the iTunes 7.4.1 update, this workaround no longer worked, meaning Apple deliberately has tried to block it. A post on Engadget however, showed that after repeating the older steps like before, and renaming the .m4r file to .m4a, when plugging in an iPhone the file will be added to your syncable ringtones list without an error message it had been showing before.
Getting ringtones from the iTunes store costs 99c.
Source:
Yahoo (Macworld)
Written by: James Delahunty @ 8 Sep 2007 19:49