i am no expert in php and query, however i put this code together which could probably be turned into a function (used in category.php):
<?php
//get the cat id of this category,
//or alternatively set it to your specific cat
$cat_id = get_query_var('cat');
//get all posts with this cat
$postwithcats = query_posts('cat='.$cat_id.'&posts_per_page=-1');
$i = 0;
//go through all thesse posts
foreach ($postwithcats as $postwithcat) :
$postid=$postwithcat->ID;
//get all comments for each post
$comments=get_comments('post_id='.$postid);
if($comments):
//get the text of each comment and save it in array element
foreach ($comments as $comm) :
$thiscomment[$i] = $comm->comment_content;
//instead of comment content you could save date or author,
//or save these data in another array
$i++;
endforeach;
endif;
endforeach;
//all comment texts of this specific cat are now in this array
//if it is needed and comments exist, echo each of them as output
if($thiscomment):
foreach ($thiscomment as $key => $val) {
//before or instead of echo you could perform other actions,
//such as sort the array elements, shorten the output
//but in this example simply
//output the whole comment text of each comment for each post of the category
echo $val;
//add space between comment output
echo '<br /><br />';
}
endif;
?>
i briefly tried the code, but it is not extensively tested ??