How can I set up an alternative X11 window manager in Mac OS X 10.6? I've tried to install an X11 window manager in Mac OS X 10.6.5 such as ratpoison via fink, but I can't get it to start.

I am also thinking about getting xmonad to work in 10.6.5, does anyone know how to set up such a window manager?
The Xmonad help page on HaskellWiki has brief instructions for getting Xmonad running on Snow Leopard. You may need to read through the instructions for older versions if some problems arise.