Sites like musicvideogenome.com and tubalr.com (and netflix) make me want some sort of app or widget that can scrape/redirect video from a portion of my browser or screen and turn it into a source that VLC can multicast across my network.
There are solutions (if you google) for live screencasting a part of your desktop to the web. If you want to skip the step of uploading to web, seems you could always remote in to the computer from another terminal and adjust the window so it show just the video?
What I am looking for is a simple, inexpensive (free), way to multicast a part of my screen to various unused monitors around my place. So I can pretend to be Best Buy, or a pub and have all my monitors from living room to bedroom to bathroom all be showing the same YouTube video or netflix movie.
For instance, for audio, I used squeezeserver. VLC can do something similar if it's given a VLC friendly source (which seems from my experience to basically be a hardware device.)
VLC doesn't solve the problem of synchronization that squeezeserver addresses, but it does make the multicasting and display portion of the problem easy.
I don't know of anything (for free or inexpensive) that can do that yet....