I like Xmonad much better than any other window manager (on any platform), but the default mod key is Alt, which interferes with Emacs and Conkeror.
Here is how to remap the mod key in Xmonad
Or, locally copied on Aug 09:
Binding to the mod4 (often 'Win') key. Put this in yout xmonad.hs:
main = xmonad defaultConfig
modMask = mod4Mask