Hi,
xlanguage is by far the best multilanguage plugin I have tested. I am using it on http://www.privat-wohnung-hamburg.de/, but there is one thing I can not solve yet. My Blog URL and My Wordpress URL (general settings) are different, due to my centrally hosted domains. My wordpress URL ist something like http://web174.xxxx.xxxxx/wordpress and my Blog URL is already mentioned above. By using xlanguage the url rewrite has some trouble. Inside the Blog links are shown correctly (like: http://www.privat-wohnung-hamburg.de/lang/de/home), but in the URL bar it shows web174.xxx.xxx.xxx/wordpress/lang/de/home. Actually I am using wordpress 2.8.2 which is not supported by the plugin right now, but maybe there is some workaround. I will definitly donate!
Alex