In GoogleCustomWikiSearch.php, line 16, Please replace
$dir = __DIR__ . '/';
with
$dir = dirname(__FILE__) . '/';
otherwise I get:
Warning: require_once(__DIR__/GoogleCustomWikiSearch.Settings.php) [function.require-once]: failed to open stream: No such file or directory in /xxx/extensions/GoogleCustomWikiSearch/GoogleCustomWikiSearch.php on line 25
Fatal error: require_once() [function.require]: Failed opening required '__DIR__/GoogleCustomWikiSearch.Settings.php' (include_path='/xxx:/xxx/includes:/xxx/languages:.:/:/usr/local/php/pear5') in /xxx/extensions/GoogleCustomWikiSearch/GoogleCustomWikiSearch.php on line 25