When form meets function you have the convertible bag. These have been the celeb favorite lately. Remember Reese and her Lanvin? As well, Ashley Olsen's all about it. When worn as a satchel, the long strap hangs in a cool lackadaisical fashion; when worn as a shoulder bag, it looks travel ready. The convertible bag is even more convenient than the car, if you ask me. Here are some fab favorites.