How can I use user input to build the URL of a GET form submission?

Question

As explained here, and based on the answer given to that previous question, I'm trying to build a custom form that will act as a filter to two separate views. As per the answer received, I'm trying to build the resulting URL based upon user input. Here is my function so far:

function my_search_form($form, &$form_state) {

  $form['search_value'] = array(
    '#type' => 'textfield',
    '#title' => t('Search:'),
  );

  $form['area'] = array(
    '#type' => 'select',
    '#options' => array(
      'songbook' => t('Songbook'),
      'blog' => t('Blog'),
    ),
    '#default_value' => 'songbook',
  );

  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => 'Search',
  );

  $form['#method'] = 'get';

  return $form;
}

So here's my problem: according to this comment on the forms api page, changing the #method to GET means that no submit or validate handler functions are called on form submission. How can I get access to the user submitted data if those handler functions aren't called?