Audio recording in QuickTime Pro!
I often use the audio recording feature in QuickTime Pro, and even though it is very simple, there is a lot to it. One thing that I noticed is that if you create an audio recording, even if you haven't yet clicked "Record", you won't be able to switch to another audio input in System Preferences. After changing the audio input, you'll have to create a new audio recording. There is also a volume level that is automatically at zero. The volume level lets you hook up a pair of headphones and get an idea of what you are actually recording.