Possible solution to the problem of Symbian browsers and IE8 & earlier not understanding media queries. (See http://www.quirksmode.org/blog/archives/2010/09/more_about_medi.html )

everything-else.css

body {
	// Basic styles
	// (For mobile browsers that don't understand media queries)
}

@media all and (max-width: 600px) {
	body {
		// Extra styles for mobile
	}
}

@media all and (min-width: 600px) {
	body {
		// Extra styles for desktop
	}
}

gistfile2.html

<!-- Selects IEs 8  earlier, including IE6 Mobile -->
<!--[if lt IE 9 ]> <link rel="stylesheet" href="old-ies.css"> <![endif]-->

<!-- Then IE9, Windows Phone 7 and everyone else get the full stylesheet -->
<!--[if (gte IE 9)|IEMobile|!(IE)]><!--> <link rel="stylesheet" href="everyone-else.css"> <!--<![endif]-->

old-ies.css

body {
	// Desktop styles
	// (This section for old desktop versions of IE)
	// (It will also be read by IE6 Mobile)
}

@media handheld {
	body {
		// Reset styles
		// (First we need to reset the desktop styles IE6 Mobile has just read...)
		// Basic styles
	        // (...then set the basic styles we want IE6 Mobile to actually display)
	}
}

To a degree this approach revives the problem of maintaining a separate stylesheet for older versions of IE. However, it's not as bad as it might look - the IE stylesheet is simply a clone of the 'desktop' section of the main stylesheet (with any IE-specific fixes appended), so this wouldn't be hard to automate.