WP_Query( 'posts_per_page=-1&category_name=' . $thecat )

I understand that this assigns the text from the database under category to $thecat but then how do you use that? Basically I want to display the tags per category but only on some categories. The original code works if I add a if in_category check before it but to do it in more than one category means I have to paste that code in over and over for every category. So I am just trying to get the current category and then insert it automatically into new WP_Query(‘posts_per_page=-1&category_name=blog’)

I think that’s the right logic anyway lol please correct me if I’m on the wrong track…

Anyway any help you can be would be greatly appreciated. I have successfully wasted about 4 hours on this thus far (why isn’t this native? ugh!). Using WordPress 3.0

if ( is_category() ) {
$cat = get_category( get_query_var( 'cat' ), false );
$thecat = $cat->slug;
} else {
$thecat = '';
}