I came across an excellent post about another DIY cat climber project using the Bjarnum shelves, but this time the shelves are covered with pieces of a rough-textured rug to keep kitty from sliding off. Nice touch!
The original post gives all the details on exactly how to make these shelves yourself, complete with excellent photos. There are even plans for the next phase of the project.
WARNING: There is just a little bit of inappropriate language in the original post, but the project was so well documented, I had to share it with you.
Read the post here.