gconftool-2 --direct -s --config-source \
-t bool /apps/metacity/general/reduced_resources true
Run as root. You may need to do this before gnome starts up. Perhaps do it like this:
1) open an console (CTRL-ALT-F1)
2) Run: `/sbin/init 3`
3) kill off any gnome-ish looking things ;)
4) Run the above command.
This was set to transparent in one of the beta versions, but people didn't like that for a default. Take a look at /usr/sbin/blag-firstboot. The code is in there, but commented out.