Ambrosia today released iToner, a new piece of Mac software to manage custom iPhone ringtones. iToner allows you to create iPhone ringtones just by dropping audio files on the faux iPhone interface and syncing. Best of all it does not require any kind of "modifying, hacking or having to reset your iPhone." Of course there are free ways of doing something similar, though without the nice eye candy. And rumor has it that Apple itself will shortly get into the ringtone business, though personally I'd rather pay once than be nickle-and-dimed for each and every ringtone.
In any case, iToner is available now for $15 and a demo is available so you can check it out for yourself.