It is probably a little late to reply on this.. but I just went through this search. I'm doing a 4x6 (completely digital) brag book for my girfriend, who just became a mom.. again.

I needed to do this quickly since I over committed myself with other projects. I didn't want to mail order anything since this was supposed to be a fairly inexpensive gift and I really didn't have time to wait for a shipment. I came up with the following alternatives:
1) purchase a cheap $.99 brag book, avail. almost everywhere.
2) Mail order a chipboard album. The only manufacturer that I could find that makes a standard 4x6 is Maya Road. From what I can tell they make 2 kinds, accordian (rings on 2 sides) and ring (rings on one side). I would have required that I open the rings up with pliers to pull the chip board pages out. Didn't have time to experiment.
3) Purchase a post bound 4x6 album and remove the unnecessary pages. Couldn't find one anywhere.
4) Purchase a 4x6 brag book from Hallmark.
5) Jessica Sprague gives step by step instructions on how to make one from card stock.
http://spraguelab.squarespace.com/blog/2007/11/20/so-thankful-mini-album-instructions.html
Since mine was a gift to a household with a toddler in it, I opted for the Halmark brag book. It was a little more than I wanted to pay, but I could hold it and see what I was getting.
Nic.