<?php

function archive_admin_settings(){
  
  $types = node_get_types();
  $final_types = array();
  foreach ($types as $key => $value) {
    $final_types[$key] = $value->name;
  }
    
  $form['archive_type_filters'] = array('#type'          => 'checkboxes',
                                        '#title'         => t('What nodes are available as filters'),
                                        '#default_value' => variable_get('archive_type_filters', array_keys($final_types)),
                                        '#options'       => $final_types,
                                        '#description'   => t('Whichever node type you choose here will be available as a filter to the user.'));
  
  return system_settings_form($form);
}