First, disable desktop effects to get metacity instead of compiz. Then open gconf-editor, find
/apps/metacity/general, and enable
reduced_resources. Here's a description of that option:
If true, metacity will give the user less feedback by using wireframes, avoiding animations, or other means. This is a significant reduction in usability for many users, but may allow legacy applications to continue working, and may also be a useful tradeoff for terminal servers. However, the wireframe feature is disabled when accessibility is on.
As far as I know there's no option to enable it through the GUI, gconf is the only way.