I think you want a "Post-Bound" scrapbook/album.

The binding is made from threaded metal posts which screw together in different lengths to adjust the thickness as you add new pages.

Find them at museum and archive supply companies like Gaylord or Hollinger Metal Edge.

http://gaylord.com
http://www.gaylord.com/adblock.asp?a...r=album&mpc=WW

http://hollingermetaledge.com