Audio Hijack (was Audio Hijack Pro) is an audio-recording tool that can capture any audio from applications like Skype and iTunes. It can also record from microphones or any other source that runs through your Mac.
The user interface, not too dissimilar to iTunes, is clean and simple, featuring two-panes from where you can capture audio from the usual applications like Skype, iTunes, iChat and QuickTime Player. In the pane situated on the right of your screen you can configure an array of settings, which include recording schedules, tags and a large selection of sound effects.
One handy feature that will appeal to most people is the one-touch recording feature for iChat and Skype conversations. Although you can't edit audio using Audio Hijack, you'll certainly to be able to capture audio from multiple sources quickly and easily, making this an excellent audio-recording application.