1. mod_rewrite

Options +FollowSymLinks
RewriteEngine on
RewriteCond {HTTP_HOST} ^yourdomain.com
RewriteRule ^(.*)$ http://www.yourdomain.com/$1 [R=permanent,L]

Дописать в файл .htaccess

2. Apache Redirect

Redirect 301 / http://www.yourdomain.com/

Дописать все в тот же файл .htaccess

3. PHP

header(“HTTP/1.1 301 Moved Permanently”);
header(“Location: http://www.newdomain.com/newdir/newpage.htm”);
exit();

http://www.highrankings.com/forum/index.php?showtopic=5644 (c) full article