Where is PHP.ini installed in Ubuntu 8.10?

1) PHP Web server
To find this one create a file with

<?php
phpinfo
();
?>
and run it on your web server.
/etc/php5/apache2/php.ini

2) PHP Client
To find this run this command.
$ php -r "phpinfo();" | grep php.ini
/etc/php5/cli/php.ini