What is the lightest weight display manager? I don't care about any bells and whistles; I would like to it handle logging me in, and running the window manager, with absolute minimum footprint.

I ran across enhance, the enlightenment display manager, but am not sure that I want to install all of its dependencies. Any enhance users out there who recommend it?

What features do you need from your gui? You can get even more minimal than eg fluxbox. My /etc/X11/Xsession script ends with mentions of icewm-light, twm, and even xsm which is the failsafe option that launches just an xterm iirc. If you dont need a desktop, just a monitor to run a few apps with guis, you can get real lightweight.

Hello,

OK, you've opened an additional avenue.

First, for the display manager (gdm, kdm, xdm, enhance, etc...) - I do need a graphical login (rather than text based startup + startx) since I have non-techie users on the machine. Any suggestions as to minimum footprint alternatives to the above mentioned? Is there a pretty text-mode login app out there?

However, to your question "what GUI elements do I need", I guess I'd answer:
* ability to run both Gnome and KDE apps
* movable, sizable windows
* alt-tab (or some easy to use alternative)
* ability to set background "wallpaper"
* right click or otherwise easily accessible apps menu which is updated with update-menus (or similar)

I'm currently using fluxbox; however, I notice that the rpm for OpenBox is about 10% of the size of fluxbox's rpm, which while perhaps an imprecise metric is interesting.

You might want to try http://www.pekwm.org it's a little lighter than fluxbox. I'm currently running fluxbox but have used pekwm and like it as well.

I don't mean to sound condescending, but there's nothing about a text login that requires special skills. A non-technical user who is able to enter a password at a GUI prompt can do the same in text.
That said, I did a short search and didn't really find anything other than the session managers you mentioned. I'm surprised there isn't an ncurses-based session manager....if there is, I think it needs more publicity.

All of the needs you mentioned should be available in just about any X window manager as long as you have the necessary base system set up. KDE and Gnome apps will, however most likely take a little while longer to start up since they require some things that would ordinarily already be loaded if you were running those desktop environments.
I'd say Blackbox or Openbox would be the most useable for "absolute minimum footprint". A good compromise of small and useable, however, would be fluxbox stable (the dev version is a bit heavier).
For a full-featured desktop, xfce4.