Sync playing video to what is playing on another xbmc

I've been trying to find a solution for this but when I search I keep getting answers about how to sync multiple XBMC libraries (which I already do) and A/V sync issues etc.

What I am trying to do is sync the playback of one machine to another.

Scenario1:

I get up from my living room to walk to the kitchen, as I do, the kitchen machine turns on, checks with the living room XBMC, sees that I'm 10:24 into S3E12 of Seinfeld, and syncs its playback to the same thing, so I can continue watching in the kitchen.

Scenario2:
Party, playback the same music on all XBMC installs throughout the house.

I can do the motion detection pretty easily, just need to know the commands to execute to sync the playback on a second/third/fourth machine.

I'm looking for the exact same feature. That would be awesome!

for 1, it's doable, i've been working on this kind of script long time ago.
for 2 you have to sync with other tool than xbmc i think, maybe look at squeezebox ?