Hiding PHP
   
    In general, security by obscurity is one of the weakest forms of security.
    But in some cases, every little bit of extra security is desirable.
   
   
    A few simple techniques can help to hide PHP, possibly slowing
    down an attacker who is attempting to discover weaknesses in your
    system. By setting expose_php to off in your 
    php.ini file, you reduce the amount of information available to them.
   
   
    Another tactic is to configure web servers such as apache to
    parse different filetypes through PHP, either with an .htaccess
    directive, or in the apache configuration file itself. You can
    then use misleading file extensions:
    
     Example #1 Hiding PHP as another language
     
# Make PHP code look like other code types
AddType application/x-httpd-php .asp .py .pl
 
     
    Or obscure it completely:
    
     Example #2 Using unknown types for PHP extensions
     
# Make PHP code look like unknown types
AddType application/x-httpd-php .bop .foo .133t
 
     
    Or hide it as 
HTML code, which has a slight performance hit because
    all 
HTML will be parsed through the 
PHP engine:
    
     Example #3 Using HTML types for PHP extensions
     
# Make all PHP code look like HTML
AddType application/x-httpd-php .htm .html
 
     
    For this to work effectively, you must rename your 
PHP files with
    the above extensions. While it is a form of security through
    obscurity, it's a minor preventative measure with few drawbacks.