Can you use something like Selenium to automate the Flash embed, or does it not appear in any useful manner in the DOM?
I'm not sure how to automate the process, but (being a Flash person myself) it would take about an afternoon to make a standalone app that could run outside of the browser. It could be either a standard "projector" (.exe/.app) or something fancy like AIR.
I use Stickam for the bang. comedy theater webcam.
It has many of the same weaknesses as justin.tv (login and automation challenges), but not quite all of them (it still works when minimized/screensavered). So it might be a small step up.