<p>i was wondering how you deal with permalinks on international sites. By permalink i mean some link which is unique and human readable. </p>

<p>E.g. for english phrases its no problem e.g. <strong>/product/some-title/</strong></p>

<p>but what do you do if the product title is in e.g chinese language??
how do you deal with this problem? </p>

<p>i am implementing an international site and one requirement is to have human readable URLs. 
Thanks for every comment</p>

If memory serves, you're only able to use English letters in URLs. There's a discussion to change that, but I'm fairly positive that it's not been implemented yet.
that said, you'd need to have a look up table where you assign translations of products/titles into whatever word that they'll be in the other language.  For example:
foo.com/cat will need a translation look up for "cat" "gato" "neko" etc.
Then your HTTP module which is parsing those human reading objects into an exact url will know which page to serve based upon the translations.