Caching and the #Google_AJAX_Libraries — statichtml.com
►http://statichtml.com/2011/google-ajax-libraries-caching.html
using #Google ’s #CDN to load #jQuery isn’t likely to benefit the majority of your first-time visitors. You’re almost certainly better off bundling jQuery up with the rest of your site’s JavaScript and making sure you’re serving long-lived #cache controlling headers with it.