Capture a link and perform an animation before navigating to it

beforeNavigation.js

$('a:not(.external').on('click', function(e) {

    // Detect if the ctrl key is pressed (indicating opening in a new tab)
    if (!e.ctrlKey) {

        // Cache variables for speed
        var $this = $(this);
        var href = $this.attr('href');

        e.preventDefault();

        // If the current url is not the same as the link href
        if (window.location.href != $href) {

            // If the current link is a mailto
            if (href.indexOf('mailto') > -1) {

                // Send people to the link (open email client in)
                window.location = href;

            } else {

                // Perform 'outbound' animations
                $('#content').fadeOut( function(){

                    // Send people on their way after animation callback
                    window.location = href;

                });

            });

    }

});​

You can use the Wordpress Plugin WP External Links to set the class of .external on the links as well as a whole bunch of other things.