Show all products in a category and subcategories

Hello I am working on a site that sells books, DVDs and games, the category list is like so:

Books
-Childrens
-Cooking
-Fiction
-etc...
DVDs
-Action
-Childrens
-Horror
-etc...
Games
-FPS
-Puzzle
-RPG
-etc...

When you select the top category of books I would like the cart to list the subcategories at the top of the page like it does in normal use and then underneath display all of the products within the subcategories. Then when you select a subcategory it filters the results.

I have searched with no usable results, is this possible?

Regards
Jim

It is not in Plugins, but there are several related but different mods for this kind of thing posted in this thread: http://www.zen-cart.com/showthread.php?83008-Display-all-categories-products-on-one-page&highlight=products+main+page

You will need to research the thread, as some that might be appropriate for you are posted later.

Thank you, I've had a read through this thread and think I have found the code to get me started with a little modification. Once the lemsips kick in properly I'll have a go at getting it working.