I have been searching for a solution for the way the categories appear on my blog. I am happy with the way each blog post appear in the url under its respective category. But when I am browsing for the individual category archive, it was showing me an additional directory called category. Example, it was showing, redblogger.net/category/china/ but no more. I found the solution. I got the following wordpress category hack to show it as redblogger.net/china/ Thanks to Jclark.
Here is the code to be placed just before the category list (most probably in your sidebar.php).

< ?php
function fix_category_links($content) {
$content = str_replace('/category/', '/', $content);
return $content;
}
add_filter('list_cats', 'fix_category_links');
?>

If you got it working, I would appreciate a link to Jclark or to this post.