In my never-ending search for frivolous Firefox add-ons, I've discovered Broadcasts Monitor, a unique twist on the idea of watching live video streams. Hang on to your hat here, because this add-on lets you slap up to 25 live video streams onto a single browser tab.
Why you'd ever want to go all the way to 25 is beyond me, but sticking with the default of four proved to be quite useful in my go with it. It supports a handful of services like Justin.tv, Ustream, Livestream, and BlogTV. Advanced users can also plug in motion JPEG video streams and Microsoft media server channels. The key thing here, is that it will take them all--you just need to plug in the URL. There are also no size toggles to mess about with, as it scales all the videos to the size of your screen.
Now, coming back to the usefulness of something like this: if you're a fan of live broadcasts, this is one of the easiest ways to get your fill on one page. You can simply add all your favorite shows and have them within reach each time you feel like watching something. It also solves the problem of watching multiple programs within one browser window if you're on a machine that's short on screen real estate. As for watching them all at once though--I'm not sold.
There are a few things that might bring your experience down, but that can be expected from most local browser add-ons. The first is that you cannot take your selection of programs from one computer to another, so if you're trying to ferry over your list of shows from a work machine to a home machine, you're out of luck. Second, because it's simply embedding the players of the live streams, you're likely missing out on the user chat you'd be getting if you were watching these on the streaming site itself. That said, it can offer a leaner and cleaner experience since there's nothing else on the page but the video you want to watch.
I'm keeping this one installed for now. The main reason being that it's properly non-intrusive; you can toggle it open in a new tab whenever you please with a little shortcut that sits in the bottom right hand corner of your browser. That, and I think it might do me some good to start watching astronauts and owl hutches alongside whatever tech conferences are being streamed.