.cat exercise wheel plan (instruction).
An exercise wheel for Cats! My cat needs one of these! [Would be neat, if mine would actually use it]
House cats possess a natural hunting instinct, and this product helps them expend that pent up energy. It's an exercise wheel for cats! Now that this project has been funded, you may order a wheel from http://onefastcat.com
The Exercise Wheel IKEA Cat Hack
jill y.: How to Build a Cat Exercise Wheel, Part 1
Go Cat Wheel - cat exercise wheel, New Design, Easy to Assemble, Budget Friendly
CAT Exercise Wheel Plan | eBay
Cat wheel - the site isn't in english, but the picture shows the simple design for a cat wheel.
LooLoo Cat Wheel And Cat Tower...... I Have GOT To Build One Of These!!!!!
Not sure if it would work, but awesome idea. Fab.com | Cat Exercise Wheel