Multiple Audio Streams?

I'm wondering if there is an application that will allow the computer to route multiple audio streams out of my Mac Pro. or- if anyone knows how to create an easily switchable audio routing panel rather than going through preferences.

Eg. I'm playing Itunes (or hulu or netflix) through my audio line out through my Samsung TV thorough a speaker system to watch online content through the TV and I want to work on files on the computer at the same time, say edit video using FCP and routing that audio through USB speakers at the desk.

Being able to create multiple audio stream routing would be a HUGE asset for someone like me. Even if it's not possible, I would certainly love it if Apple would incorporate a quick switch selector in the pulldown menu for audio volume...

Thoughts? Anyone?

Thanks!