How to call a module in a block or give a module a block or put module form into a block?
You can do this with the $form_id and the function drupal_get_form();

You need to create a module and use hook_block():

function mysecondmodule_block($op = 'list', $delta = 0, $edit = array()) {
  switch($op) {
    case 'list':
      return array(array('info' =&gt; 'mymodule add block'));
    break;
    case 'view':
      if($delta == 0) {
        return array(
         'subject' =&gt; 'Mymodule Add',
         'content' =&gt; drupal_get_form('form-id');
        );
      }
    break;
  }
}