Another method that I have

webwiz — Mon, 01 Jun 2009 18:13:58 +0000

Another method that I have used - Server Side Includes. It's very likely that these are available on your host - if not, ask them to allow them for you. Way simpler than PHP, too, IMHO.

A PHP include would be ideal

greg — Mon, 01 Jun 2009 12:43:02 +0000

A PHP include would be ideal here. Include a file in that area on all pages and just update the one file when needed.
The include code wouldn't need to be changed as long as the included filename stayed the same.

<?php
//whats new area
include_once('whats_new.php');//can be a .txt, .html .. etc
?>

As you use HTML files, you will need to either change them to .PHP wherever you have the "What's New" OR put a re-write rule in the .htaccess file.