Yes, I actually just saw this code snippet on a live site today.

platformSniffer

function platformSniffer(macURL,os2URL,linuxURL,winURL) {
location.href = winURL;
        var agt=navigator.userAgent.toLowerCase();
        var is_major = parseInt(navigator.appVersion);
    var is_minor = parseFloat(navigator.appVersion);
    var is_nav  = ((agt.indexOf('mozilla')!=-1) && (agt.indexOf('spoofer')==-1)
                && (agt.indexOf('compatible') == -1) && (agt.indexOf('opera')==-1)
                && (agt.indexOf('webtv')==-1));

        var is_mac    = (agt.indexOf("mac")!=-1);
        var is_os2   = ((agt.indexOf("os/2")!=-1) ||
                    (navigator.appVersion.indexOf("OS/2")!=-1) ||
                    (agt.indexOf("ibm-webexplorer")!=-1));
        var is_linux = (agt.indexOf("inux")!=-1);
        var is_win   = ( (agt.indexOf("win")!=-1) || (agt.indexOf("16bit")!=-1) );
    var is_win95 = ((agt.indexOf("win95")!=-1) || (agt.indexOf("windows 95")!=-1));
    var is_win16 = ((agt.indexOf("win16")!=-1) ||
                   (agt.indexOf("16bit")!=-1) || (agt.indexOf("windows 3.1")!=-1) ||
               (agt.indexOf("windows 16-bit")!=-1) );
    var is_win31 = ((agt.indexOf("windows 3.1")!=-1) || (agt.indexOf("win16")!=-1) ||
                    (agt.indexOf("windows 16-bit")!=-1));
    var is_win98 = ((agt.indexOf("win98")!=-1) || (agt.indexOf("windows 98")!=-1));
    var is_winnt = ((agt.indexOf("winnt")!=-1) || (agt.indexOf("windows nt")!=-1));
    var is_win32 = (is_win95 || is_winnt || is_win98 ||
                    ((is_major >= 4) && (navigator.platform == "Win32")) ||
                    (agt.indexOf("win32")!=-1) || (agt.indexOf("32bit")!=-1));


        if (is_mac) { // Macintosh
        location.href = macURL;
         } else if (is_os2) { // OS2
   //location.href = os2URL;
   } else if (is_linux) { // Linux
        //location.href = linuxURL;
   } else if (is_win || is_win95 || is_win98 || is_winnt || is_win31 || is_win32 || is_win16) {
   location.href = winURL;
    }
   }