Sure. I originally did this for a prospect under 3.2.1, but they went away. Since so many people seemed interested, I went ahead and setup a generic test 3.3.1 site and made only this change. I will be pulling this site down to build my next project, but will leave it up for a couple days max.
http://www.freerangeminds.com/shop/
Just the generic 3.3.1 demo products. Remember that this only displays the category and subcategory (1 level). Any deeper and it will only leave the subcategory displayed.
-Derrick