So I've been trying to figure this out for a while now:

I'm trying to find a way that I can patch different audio sources (both hardware and individual applications) to different outputs.

For instance: If I wanted to listen to iTunes in my headphones via the built in output and I wanted my system sound to come out of my computer speakers via the line out.

I've found various applications that will take sound from individual applications and patch them into another application (eg. audio from skype to logic). I've also found various applications that will patch sound from a hardware input to a hardware output.

If anyone knows how I might accomplish this it would put an end to my frustrations and would be much appreciated.