Solve This: Binding Issues

Sue needs help finding a way to bind cards. She writes, "I have a project: 5 each 2-sided (cardstock) small laminated reference cards that need to be bound together somehow, but not as a booklet.The only method I can think of (or find locally) is grommet and chain, but that's not very attractive. The cards will be used a lot and need something durable. Does anyone know of some other methods?" Discuss it!