To see more design walls check out Judy's blog.
Now the big project that's done...from this...
I don't know if the cat is going to enjoy it right away, but I think she will eventually. She is still a little tentative, so it might take her a bit. We don't have it attached to the ceiling beam yet, and I don't know if we'll need to. She only weighs about 10 pounds so it probably won't wobble. It is 8 feet tall and 24 inches in diameter. the circles are 16 inches (pre-cut and available at Lowes). I still have to adjust the top "room". It's a bit too close to the one below so she can't quite get in there, but I only screwed it into the three poles, so it won't be a problem.
I ended up doing most of the work myself. Joe was gone all week at a retreat, so other than covering the poles, I did everything else. I got a couple of nicks and scratches, and my back hurts some, but I feel good about the whole thing.