Real-time window manager switching

[csj <csj@mindgate.net>]

I treat window managers like themes or skins. Depending on the mood and
need I run WindowMaker, Fluxbox, IceWM, Ion and (because of a recent
thread) Ratpoison.

With mouse-centric WM's like WidowMaker, I can change WM's simply by
pointing to the corresponding "Window Manager" menu entry. With
keyboard-centric WM's like Ion and Ratpoison, I need to figure out the
precise commands to map to the key bindings.

I managed to find out Ion's "restart_other" option, but with Ratpoison I
appear to be trapped. I need to log-out of my XSession before I can
change WM.

So, is there a shell command sequence which I can type into an xterm to
replace Ratpoison with another WM, while keeping my other X clients
still running? I need the equivalent of a re-startx.