This ant task will automatically clear your Drupal cache with every build/save. Gone are the days of logging into the admin panel to clear the Drupal cache to preview your template or modifying Drupal to get around it!

build.xml

<!--
     1. Download and add drush to your template folder or put it somewhere on your computer and symlink it - http://drupal.org/project/drush
     2. Add the following task to your Ant build file after your deployment tasks
     3. 'dir' is the path to your local deployment i.e. /Users/yourname/Sites/yourwebsite/public_html
     4. 'executable' is the path to your drush command. Simply use drush in this attribute if you have symlinked it
-->

<exec dir="${path.deploy}" executable="${directory.build.tools}/drush/drush" failonerror="true" output="/dev/null">
    <arg line="cache-clear all" />
</exec>