Apache performance tuning - Expires Headers

With the advent of YSlow, we should all now be aware of adding expires headers to our web servers. For my purposes, I wanted to enable it globally, then fine-tune per Virtual Host.
In my Apache httpd.conf, I added the following directives:

<ifmodule mod_expires.c>
<filesmatch \".(jpg|gif|png|css|js|swf|ico)$\">
ExpiresActive on
[...]

Utilizing mod_deflate & zlib for web performance

Every webmaster is looking for ways to enhance performance. I’ve researched the web and found some hits and some misses. Here are a couple changes that have dramatically improved Apache and PHP performance for me. Of course, this is my implementation, and I’d like to hear from others how I could improve.