search by price in a category

I've tried a couple of "search by price" sideboxes which work but not in the way I want. They display all the products in the selected price range regardless of category. I want to show products within a price range in a particular catgory or sub-category. So if I'm in the widgets category and displaying all the widget products I would like the visitor to be able to display all the £0-£10 widgets, £10-£20 widgets, and so on.

I would like the visitor to be able to display all the £0-£10 widgets, £10-£20 widgets, and so on.
,If you are seeing the product listing when a cat is selected, try clicking the heading "Price" it will sort by price > click again and it will sort the reverse of the initial sort