I have realized that a few people here mentioned that you cannot capture parse errors (type 4, E_PARSE). This is not true. Here is how I do. I hope this helps someone.

1) Create a "auto_prepend.php" file in the web root and add this:

<?php
register_shutdown_function('error_alert');

function error_alert()
{
        if(is_null($e = error_get_last()) === false)
        {
                mail('your.email@example.com', 'Error from auto_prepend', print_r($e, true));
        }
}
?>

2) Then add this "php_value auto_prepend_file /www/auto_prepend.php" to your .htaccess file in the web root.

* make sure you change the email address and the path to the file.