"This tutorial explains how you can configure Apache2 to set the
Expires HTTP header and the max-age directive of the Cache-Control
files) to a date in the future so that these files will be cached
by your visitors' browsers. This saves bandwidth and makes your web
site appear faster (if a user visits your site for a second time,
static files will be fetched from the browser cache). This tutorial
was written for Debian Squeeze."