It should be known that XFree86 (under standard binary downloads) supports only the primary monitor.

I current use 2 monitors primary for big GUI apps and a smaller one for "Terminal.app" work for multiple shells & casual Web Browsing.

Upon launch, X Windows & Aqua Cmd+Option+A nicely, while I still get to use my 2 monitor for OMNI Web or whatever.

Later, Markus.