Creating a dynamic menu link in Drupal

function grasmash_menu() {
  //create menu item for My Company
  $items = array();
 
  $items['my-company'] = array(
    'title' => 'My Company',
    'description' => 'View your company\'s page',
    'page callback' => 'grasmash_my_company_link',
    'access callback' => 'grasmash_user_has_company',
    'expanded' => TRUE,
    'weight' => -100,
    'menu_name' => 'primary-links',
  ); 
 
  return $items;
}

//find user's company. this assume that each user only belongs to one company!
//for admins, will choose the most recently joined company that user is an admin of
function grasmash_get_user_company(){
  global $user;
  $nid = db_result(db_query("SELECT og_uid.nid, node.type FROM og_uid, node WHERE og_uid.uid = %d AND node.type = 'company' AND node.nid = og_uid.nid ORDER BY og_uid.created DESC, og_uid.is_admin DESC LIMIT 1", $user->uid));
  return $nid;
}

//does the user actually belong to a company?
function grasmash_user_has_company(){
  if (grasmash_get_user_company()){
    return TRUE;
  }
}

//redirect the user to the right node
function grasmash_my_company_link(){
  $nid = grasmash_get_user_company();
  drupal_goto('node/' . $nid);
  //return node_view($nid); //you could also simply load the node if you wanted to
}