Module to record the username of a user when they access a page?

We've been asked to come up with a module that can be embedded in a page and will insert into a database table the username of the user accessing that page.  I've tried Google searching but can't find anything.

I did find a forum post that talks about doing something similar:

• Create the table using:

  CREATE TABLE `databasename`.`jos_names` (`id` int(11) NOT NULL auto_increment, `firstname` VARCHAR(100), `lastname` VARCHAR(100), PRIMARY KEY  (`id`) )

• 
  Then write your module using: $db =& JFactory::getDBO();
$query = "INSERT INTO `#__names` (`fname`, `lname`)
VALUES ($fname, $lname);";
$db->setQuery( $query );
$db->query();