I have an HTPC (with an HDTV as the monitor) running Ubuntu Karmic, and various other computers in the house. Sometimes I want to run X11 applications (usually, but not always, XBMC) on the HTPC displayed on the HDTV, but I don't want to have to physically go to the HTPC to do so; I want to do so from another computer in the house.
If I use ssh then, of course, the applications don't run because X isn't started on the connection. I don't want to use ssh -X or ssh -Y because I don't want to forward the display to my laptop: I want to do things in the X session already running on the HDTV. I don't want to use VNC or its ilk because sharing a 1080p display over an 802.11g network is nobody's idea of fun.
What I want is a command to run in a remote bash shell that executes in the local X session. Any ideas?