On PHPBuilder.com today there's a new post from Vojislav Janjic with three methods (sans-framework) that you can use to create a multilingual website - some a bit easier to maintain than others.
Fast internet growth has brought many opportunities in the global market. Businesses can reach their customers across many countries, and information sharing is not limited to a local area or country anymore. This is why there is an increasing tendency for multilingual websites. By having a website in multiple languages, you can target local markets more easily. Also, it is more convenient to use a website in your native language.
His three methods are all relatively simple, but they all have their good and bad points - making separate HTML/views for each language, creating XML files with different versions of the content or storing the translations in a MySQL database. He gives quick code snippets showing how to implement each of them, some basing the language on a cookie value, others on a GET variable passed to the page.