How many unique visitors you’ve got last month? I bet the number is still under 1 billion, right?

So you’d better use Google’s copy of jQuery instead of yours. If your user still has the cached file of Google’s website (or from many other sites that uses its Content Delivery Network (CDN)) their browser will just get the cached version, improving a lot your website’s performance.

You can use it by copying & pasting this HTML:

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<script>window.jQuery || document.write('<script src="js/libs/jquery-1.7.2.min.js"><\/script>')</script>

In SharePoint scenarios this is very useful in Internet Websites and in Intranet sites where you now the local network has internet access.

Find more JQuery tips on http://webdesignledger.com/tips/9-jquery-mistakes-you-shouldnt-commit