Fallback

<script type="text/javascript" src="http://ajax.microsoft.com/ajax/jquery/jquery-1.4.2.min.js"><... <script type="text/javascript"> if (typeof jQuery == 'undefined') { document.write(unescape("%3Cscript src='/js/jquery-1.4.2.min.js' type='text/javascript'%3E%3C/script%3E")); } </script>

another reminder that using a third party CDN just just another point of failure you add to your site.

I think visitors might have a higher chance of having a cache jQuery from google CDN.

Their SSL cert just expired.... How much of the internet is down right now? :P