Detach X11 app and reattach on another?
Solution 1:
VNC will do this for you. It's the Unix version of remote desktop.
Solution 2:
http://en.wikipedia.org/wiki/Xpra sounds more like what you want to do than VNC..
Solution 3:
Other things that let you suspend and resume remote X sessions would include:
- Exceed onDemand (popular in the corporate / education worlds)
- NoMachine NX / the free wrapper for their GPL libraries, freeNX / Google's 'neatX' NX server
Solution 4:
Have you tried shifter?