You can make your WordPress website to use common JavaScript libraries from Google AJAX Libraries CDN in order to make it fast as it enables users to download jQuery faster than before.
How this works? Various JavaScript libraries distributed with WordPress are also hosted on Google’s AJAX Libraries API. Hence, you can use that content distribution network over your WordPress website rather than serving these files from your WordPress installation.
Use Google Libraries is a WordPress plugin that automatically does this job on any WordPress website.
All you got to do is install-activate this plugin and that’s it. It takes load off from your server, increase chance for user already has these files cached, uses compressed versions of the libraries wherever available and Google’s servers are set to negotiate HTTP compression with the requesting web browser.