Ringtone creationism not for sale in iTunes 10, but DIY method still seems to work

Not that we've ever been a fan of paying an additional 99 cents to turn an already-purchased track into a seconds-long ringtone, but if you fancied the option in iTunes 9.2.1, we're sad to inform you that yesterday's update seems to have nixed said option. But hey, look at this way, now you can learn a new skill: how to make iTunes 10 ringtones free of charge with some filename finagling. The old method still seems to work just fine (instructions via More Coverage link below), so turn that .m4-frown upside down!