dynamic exclude a post from a list of post?

Greetings all,

I need a list of post from a certain category but the list have to exclude that post, the list is showed on …

I got it working with pages:

<?php
if (is_page()) {
$page = $post->ID;
$exclude = $page;
wp_list_pages('title_li=<h2>Pages without the currently view page/tree</h2>&exclude_tree='.$exclude );
}
?>

But I cant find the way to make it work on post.

The background:

Lets say I got 10 post in a category named “guides”. When you read one of the guides, I want you to se the other 9 post in that category (in the sidebar og something)

thanks

ras