Does anybody know where I go to remove Page titles?
I'm using WordPress 2.8.4 and Atahualpa 3.4.1

Under Style Posts and Pages go to the Headline Box and enter display:none;

lmilesw's suggestion is a good one, but be aware that if you enter the 'display:none' then you won;t see eithor page or post titles.

If that is what you want, then you could also go to ATO->Style & edit CENTER COLUMN->The LOOP and remove the line

<?php bfa_post_headline('<div class="post-headline">','</div>'); ?>

which would reduce the number of lines of code being run

If you ONLY want to prevent the PAGE titles from displaying, then change the line above to

<?php if (!is_page()) { bfa_post_headline('<div class="post-headline">','</div>'); } ?>

would it be possible to remove just the titles from the multi post pages such as search, categories lists, archives...?

Rashell, do you want to remove the SIDEBAR's? or are you asking if you can remove the TITLE's of the WIDGETs in the SIDEBARs?

When you ask a question, please be as detailed as possible.

I wanted to know how to hide post title for a specific category. I want the title to appear in the browser tab but not on the page. But how do i do that?

If you're using Atathualpa, just insert
display:none;
in the theme options for Header Box: Text:
Appearance/Atahualpa theme options/Style POSTS & PAGES