Screen share TO xbmc FROM ubuntu laptop

I would like to emulate the features found in OSX Mountain Lion, where it is possible to "Airplay" videos from a laptop screen to an Apple TV. However I would like to instead send videos displayed on my ubuntu laptop screen (possibly flash based) and have them show up on my XBMC set-top box (also ubuntu). In other words, I want to do some of my TV "channel flipping" from my laptop. I already have an add-on installed from my mac (safari) that sends youtube url addresses to xbmc, but that has ceased working.

It seems to be that this should be possible, but my searches seem to assume that I want to stream FROM xbmc and not TO xbmc.

Thanks