iToner

iToner is a ring-tone creation tool for the iPhone. It supports MP3, WAV, AAC and AIFF files. Unlike other similar applications out there, iToner allows you to directly connect to your iPhone to send your newly created ringtones over.

This doesn't require you to install any software on your iPhone, though. All that is needed is that you connect your iPhone by plugging it into the USB port of your Mac when you start the program. You don't even need iTunes.

When an iPhone is detected, you can start using the app. The first step is to drag and drop a song file onto the interface. This will add the song to a list. From there, you can simply click the "Begin sync" button at the bottom of the user interface and the song will be sent to your iPhone. Additionally, you can crop the song. By clicking on the button with the scissors, you will be shown a slider, which you can drag to determine what part of the song you want to use. The song will be played as you move this slider to help you choose the right beginning and end points.