The wife and I built a nice pole that the cats can climb up to get to the space above the living room that they like to run around in.  Before they would need to jump on the counter and then the refrigerator or their other cat tree/scratch post to get up there.  This was actually a pretty good idea that worked out fairly well.  Cats seem to enjoy it anyway and it hardly takes any space and doesn't look too bad.

This was made using a 4x4x10 wooden pole, a 6x9 area rug (indoor/outdoor cheap thing we bought at Costco) stapled to the pole, and some sisal rope on the bottom where the cats can scratch on it.  It has a small base just to have something down below but it is attached on top to the wall with some L brackets to make sure it won't go anywhere.  It took about 6 hours to build, most of which was using a hot glue gun to glue the rope to the bottom of the pole.