You can easily customize the text used for [more] in your posts using the new custom field feature in WP. Find the line in your index.php that says:
<?php the_content(); ?>
And replace it with this:
$somemore = '(more...)';
$maybemore = get_post_custom_values('more');
if(count($maybemore) > 0) $somemore = $maybemore;
With that code in place, when you add a custom field called "more" to any post, it will use that text instead of the default. The default is the "(more...)" in the code above.