MP4 object: 10.8 webkit browsers "Missing Plug-in", other browsers display video via QuickTime
On modern browsers your best bet is to use the HTML 5 video tag.

&lt;video width="494" height="388" controls autoplay&gt;
 &lt;source src="http://server.site.org/path/filename.mp4" type="video/mp4"&gt;
 Your browser does not support the video tag.
&lt;/video&gt;


You can put your fallback code where it says "Your browser does not support the video tag.".