[ALUG] How to get rid of gnome?

So who is a Fedora expert? How do I get rid of the (vaguely horrible) Gnome desktop on this here Fedora machine and then choose a more acceptable window manager? OK, I can do the choosing and installing of the Window manager I want as I have done that on my home machine. However I can't see how/where to find the hooks that gnome uses to start the gnome desktop. The system is running gdm by the way, which is OK but I can't see where *it* decides which window manager to start. If it's easier I'm quite happy to ditch gdm and use something else (or even nothing, run startx directly). -- Chris Green