Let\'s say I have two categegories, A and B.
I set A to use \'layout_a\' on Catalog -> Catalog Categories -> Click a category -> click custom design tab
I se
In the current versions of Magento there is another way to do this without changing core code. Lets say you have a custom template for the product display of a category. In Admin go to Catalog->Categories->Manage Categories and select the category you want to apply the modified product template to. Change "Apply to Products" to Yes and put the following in the Custom Layout Update;
catalog/product/NEW_VIEW.phtml
Where NEW_VIEW is the name of the new template you want to use. If you have sub-categories you may need to have their "Use Parent Category Settings" set to Yes in order for it to float through.