cachme is a very simple caching system for PHP pages, based on the technique described at http://www.snipe.net/2009/03/quick-and-dirty-php-caching/ but packaged in a reusable script.
To use cachme, simple include it at the very top of the script you wish to cache:
<?php include('cacheme.php'); ?>
Also make sure the cache directory ("cache" in DOCUMENT_ROOT by default) exists and is writable by the webserver.
You can change the expiration time per file by setting $cacheme_expires (number of seconds) before including "cacheme.php".
Custom headers such as content types aren't cached, etc.