Show/hide categories on main page/showing to logged in customers only

[igi2011]

Hi all,
I've got a couple of questions regarding categories.

Firstly I want to display only a few categories in the centre column and hide the rest, however I want the remaining categories (which I'm linking to on the left) to remain active.

Secondly, is there any way to hide a whole category and its sub-categories from view until a customer is logged in?

Website is in stan t-gi fts.co.uk

Many thanks
Lee

[igi2011]

Please ignore the first part of my message as I've figured out a workaround using custom centre boxes and sideboxes.

However my second question still stands... we already have a system in place where prices are hidden until the customer logs in, but I'm not sure how I can hide a whole category.