Simple jQuery plugin to toggle between shown/hidden states.

jquery.visibility-toggle.js

/**
 * Simple jQuery plugin to toggle between shown/hidden states.
 *
 * Markup:
 *
 * <div class='box' style='width: 50px; height: 50px; background: red; padding: 20px;'>Box</div>
 * <button>Toggle</button>
 *
 * Usage:
 *
 * // The box will toggle its visibility every time user clicks on `button`.
 * $('button').click(function() {
 *   $('.box').visibilityToggle();
 * });
 */
(function($) {
  $.fn.visibilityToggle = function() {
    var context = $(this),
        isHidden = context.css('display') === 'none';

    if(isHidden) {
      context.show();
    } else {
      context.hide();
    }
  };
})(jQuery);

Turns out that using the native toggle() method without any parameters will toggle visibility.