I love this case http://www.sanseven.com/classic-collection-iphone-case-p-21.html. It has the smallest profile of all of the iPhone 4 cases I've seen, and doesn't detract from the form factor. I especially love the texture of the case - it feels silky in your hand, and has just enough grip to keep it from slipping, but not too much to make it difficult to move in and out of a pocket. Amazingly, it also provides good protection, and has saved my iPhone from destruction in numerous falls. Highly recommended.