This module gives Drupal the ability to easily change links into popup dialog boxes.
There are a couple of ways to use this module.

#1) Add the popup class to an existing link, either in code:
  popups_add_popups();
  $output .= l("Pop up entire local page.", 'popups/test/response', array('attributes' => array('class' => 'popups'))) ."<br />";

or on the theme level:
  <?php popups_add_popups ?>
  <a href="popups/test/response" class="popups">
  
class="popups" requests an informational popup.
class="popups-form" requests a popup with a form that modifies the content of the original page.

And you can use the psedo-attribute, "on-popups-options" to send options, if you don't mind having non-validating HTML.
The advantage to this attribute, is that it will be removed from user content by the HTML filter.
ex: print l("Pop with options (width=200px).", 'popups/test/response', 
               array('attributes' => array('class' => 'popups', 'on-popups-options' => '{width: "200px"}')
See _popups_test_popups() for more examples.    

#2) You can add a custom module that implements 
the hook_popups hook, which returns an array of popup rules, keyed by the id 
of a form, or the url of a page.
Each rule is an array of options, keyed by a jQuery selector.  No options is
equivelent to class="popup-form".

 * Rule Format Example:
 * 'admin/content/taxonomy' => array( // Act only on the links on this page. 
 *   'div#tabs-wrapper a:eq(1)',  // No options, so use defaults. Note: Selector must select <a> element(s).
 *   'table td:nth-child(2) a' => array( 
 *     'noReload' => true, // Popup will not modify original page.
 *   ),
 * )

 * Options:
 *   noReload: Does the popup NOT modify the original page (Default: false).
 *   surpressMessages: Don't show the messages the form returns in a popup (Default: false).
 *   additionalJavascript: Array of JavaScript files that must be included to correctly run the page in the popup. 
 *   additionalCss: Array of CSS files that must be included to correctly style the page in the popup. 
 *   forceReturn: url to force a stop to work flow (only use in conjunction with noReload).
 *   href: override the href in the a element, or attach an href to a non-link element.
 *   width: override the width specified in the css.