Work Out While You Work
The folks at the Mayo Clinic have designed an office which combines a desk and a treadmill so that you can work out while you work.
I could definitely use one of those. When I was younger, my family had a simple unpowered treadmill. You held on to two poles and then walked. My dad added a simple belt so that I could read while I was working out.
I'm definitely going to have something like this when I finally buy a house!