I finally got 'xdm' running and was able to log in as a regular user. I did a pkg_install and installed the gnome-desktop package, but I haven't been able to find a way to get it to work for my regular user. I created a ~/.xsession file with the following lines in it:

/usr/local/bin/metacity &
/usr/local/bin/gnome-panel &

but when I log in, X bombs out and I get sent back to the xdm login screen. If I check ~/.xsession-errors log file, I see:

Xlib: connection to ":0.0" refused by server
Xlib: Invalid XDM-AUTHORIZATION-1 key (failed key comparison)
xsetroot: unable to open display ':0'
Xlib: connection to ":0.0" refused by server
Xlib: Invalid XDM-AUTHORIZATION-1 key (failed key comparison)

I thought that maybe my assumption that ~/.xsession should work was flawed and so I became root and modified /etc/X11/xdm/Xsession and changed the 'fvwm' line to /usr/local/bin/metacity &. This didn't work either. I got the same errors and the bomb out back to the xdm login screen. So... I changed it back to 'fvwm' and now I STILL get the same bomb out and errors even though the file is back to normal. So... there must still be some lock files or something I am not aware of. I cleared our the /tmp dir again and aso got rid of any dotfiles/dirs that the were added to my regular user's home when I tried to run 'metacity' and 'gnome-panel' to no avail.