function find_all_groups_for_user($user_id)
{
    $result = array();
    // Find all possible capabilites
    $all_groups = Groups_Group::get_groups();
    // Iterate, find what capabilites the user has
    foreach ($all_groups as $group) {
        $OK = Groups_User_Group::read($user_id, $group->group_id);
        if ($OK) {
            $result[] = $group;
        }
    }
    return $result;
}