Safari 1.3/2.0 supports multiple background images according to the CSS 3 āstandardā (it's a working draft). Pretty amazing. See the blog post about it in the Surfin' Safari blog and this pretty cool demo (don't miss the sources). Should work in Konqueror, too. For the masses when 3.5 is released. No workie in Firefox 1.x.
By the way, since WebKit is now open source, I downloaded it today and compiled it (more for fun than something I really needed). Pretty straightforward and I have now a bleeding edge Safari (if I want, the regular WebKit is not replaced, fortunately).