http://slides.html5rocks.com/

notveryawesome.js

var ua = navigator.userAgent;
        var isFF = parseFloat(ua.split('Firefox/')[1]) || undefined;
        var isWK = parseFloat(ua.split('WebKit/')[1]) || undefined;
        var isOpera = parseFloat(ua.split('Opera/')[1]) || undefined;

        var canTransition = (function() {
          var ver = parseFloat(ua.split('Version/')[1]) || undefined;
          // test to determine if this browser can handle CSS transitions.
          var cachedCanTransition = 
            (isWK || (isFF && isFF > 3.6 ) || (isOpera && ver >= 10.5));
          return function() { return cachedCanTransition; }
        })();