Showing different sidebar on different pages

To show a different sidebar on different pages, replace the standard call for the sidebar:

<?php get_sidebar(); ?>

with the following code:

<?php include ('sidebar2.php'); ?>

The same can be done to call different headers, i.e. instead of <?php get_header(); ?> use <?php include ('header2.php'); ?>For more information, see Different Sidebars Anyone? on the WordPress codex.