Maybe you can experiment with this if you want in the sidebar and pages.
You will have however to strip some code and put it in two new php files called sidebar 1 and sidebar 2.
make some new template pages copy the index.php inside the new files and include one of the PHP files.
every change in the code below gives another result.
In this code only subcategory's are shown and the category's themselves are hidden to make it easier to work with template pages and subcategories.
Also in this example the number of posts are shown.
See also the codex.
<?php list_cats(FALSE, '', 'ID',
FALSE,'asc', '', FALSE, TRUE,
FALSE, FALSE, TRUE,
TRUE, FALSE, '', FALSE,
'', '', '1,6,7', /*on this line choose which cats you want to exclude.*/
FALSE);
?>
Martin