Apple might be neutral towards third-party iPhone software development, but it's apparently downright hostile when it comes to DIY ringtones -- just 10 days after releasing iTunes 7.4.1, which killed off an easy way of getting your own ringtones on the iPhone, the company has dropped iTunes 7.4.2, which obsoletes the latest ways of getting your own sounds on the phone, including popular apps MakeiPhoneRingtones and iToner. DIY ringtones still make it into iTunes' ringtones folder, but aren't copied over to the iPhone -- a problem we're certain hackers will get around sooner rather than later. C'mon Apple, we know you're smarter than to play these cat-and-mouse games.
Update: Well, that didn't take long. According to Shadowfax in the MacRumors forums, all you've got to do to get ringtones back is flip a metadata bit and change the file extension back to .m4r -- something MacRumors says is more indicative of Apple "solidifying the format" than actively trying to kill ringtones. We're also hearing iToner still works, although we've yet to confirm. Check the read link for Shadowfox's instructions.
[Thanks to everyone who sent this in]