I think it would be helpful to rethink the object categories in "shop". For instance considering how many iPhone cases (3g, 4/4s and 5) there are, perhaps it could be its own category vs. cases.
Thanks DavidTsai-- we're looking into what the best way to categorize our diverse set of models across the site is. In the meantime, you can browse by tag if you're looking for something very specific, such as iPhone 5, though it would include other accessories for iPhones. https://www.shapeways.com/search/tag?tag=iphone+5 Hope this helps a little bit