QuickTone

Designed to provide a quick and complete solution to a common need, you can easily throw different types of media files into QuickTone, preview and edit each tone to its desired length, and batch copy all the files directly to your iPhone via a wireless interface.
Type conversions, renaming and other annoyances are performed automatically for you, leaving you with a quick overall solution to use the tones you really want on your iPhone.
With QuickTone, no iTunes library limitations are enforced, and you are free to handle your tones in whichever way you see fit.

Sync with multiple computers, copy ringtones with an unlimited length and change the default SMS sounds with either pre-made SMSTones or ones you edit yourself.