How can I hide "Start a New Discussion" from the category pages?

Platon

I only want it to appear when a person is browsing inside a category, or reading a thread, is doing this feasible by mere mortals?

Rainulf

@Platon, you can go to applications/vanilla/controllers.. Choose whatever controller you need (class.discussionscontroller.php in this case). Inside public function Index($Page = '0'), you will see the following:
$this->AddModule('NewDiscussionModule');
Comment it off.

The controller directory basically contains controllers from which you can use to control little modules like the NewDiscussionModule (or button). Read this for more info.

Linc

In your theme hooks file, add this method:

public function CategoriesController_Render_Before($Sender) {
    if (isset($Sender->Assets['Panel']['NewDiscussionModule']))
         unset($Sender->Assets['Panel']['NewDiscussionModule']);  
}

Todd

You may also just want to add some css to your custom.css:

body.Discussions .NewDiscussion {
    display: none;
}