No the best way to deal with this is to add a background color then put the image over this. There really is no way that i know of to have a background image fit every monitor. You could make the background rather large, but then everyone viewing at a resoulution of 800x600 would have to scroll.
On the ghostmaster page it looks as though I have a image all over the page, but i do not. If you are viewing in Firefox then rightclick the background and be sure that your not on any text and select "view background image" you will see just how large this image actually is. It will surprise you.
The point is there is code for this, but it does not work for every browser.
‹img src="someimg.jpg" width="100%" height="100%"›
If the height is off and looks like crap then remove it, and see if that helps.