[LAU] Audio output from Flash plugin...?

Hi all, Following Ken Restivo's recent post linking to some youtube videos, I'd like to get some audio output from Firefox's Flash plugin. I mostly use JACK; is there any hope of getting it to work with JACK? If not, maybe some sort of desktop sound mixer that uses ALSA? I have an up-to-date PlanetCCRMA based on FC6, and my main soundcard at the moment is an RME DIGI9636. The machine contains an MSI K8N nForce4 board, with an onboard soundcard, which appears to have an ALSA driver. Where should I start? Maybe an appropriate setup for me in the long-term would be to use the onboard soundcard for general desktop sound (using some sort of simple sound mixer?) and JACK with one (or more) of my RME cards for audio work. Is it possible to do this in a permanent and reliable fashion? How would I go about it? I am trying out various desktop environments and window managers at the moment, and haven't settled on anything yet. Maybe I will use KDE or GNOME when I want to use my machine as a general purpose workstation, and something like fluxbox for audio. Thanks, Michael