I saw this product when I was looking for a binding system. Its by Zutter and its called Add It All. Its an strip that has openings for rings that snap into a book with an adhesive strip so that you can things like pamphlets cards and brochure right into your albums. They have a video on their site that shows you exactly how it works and I'm sure you could either midfy this to work with a post bound book or make something like it that will work. Its pretty cool. I was going to get some to put Christmas cards and anniversary cards into an album.
This is the link to their website and video: