A Business Card Holder from a Book

I did this a while ago but still love the look of it. The idea comes from the very cool Morning Creativity blog - the post DIY Book Business Card Holder. I will definitely try to do more of his DIY. My "Business card holder" in all honesty usually holds bills and I still cannot decide whether to cut the hard covers off or not - what do you think? 

P.S. A piece of advice - do not use a  book with a lot of pages. You will be folding forever :)