This plugin brings jQuery, jQuery UI and jQuery Tools to your site. It supports grabbing the libraries from both Content Delivery Networks (CDNs) and local copies, allows to activate jQuery.noColflict() mode if necessary. As well it already includes one of jQuery UI themes, uiLightness (and you can download and use any other theme).

Latest jQuery, jQuery UI and jQuery Tools versions are already included.
And you need not to depend on plugin updates: you can always use CDNs and grab the latest libraries from the Web.