<script src="//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.js"></script>
<script>window.jQuery || document.write("<script src='js/libs/jquery-1.6.4.min.js'></script>")</script>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
<script>window.jQuery || document.write(unescape("%3Cscript src='/path/to/jquery.js' type='text/javascript'%3E%3C/script%3E"));</script>
[Edit: simonsarris replied with something similar as I was replying, however, the advantage of using unescape is that you don't get invalid markup warnings]
Is this right?
Why should I have to login to facebook to view that page?
Facebook broke the internet for completely different reasons.