I've used a treadmill before and I have to agree that they are quite convenient to use when you're trying to get into shape. Treadmills are great for a variety of reasons and can easily be hacked to be used as standing desks.
However, experience has taught me that there is no substitute for taking your shoes and going outside for a run. I've actually run in rain, snow, and 5˚F weather without any problems. This includes daily runs in sweltering Taipei, where it's 90˚F after sundown without any issues. All you need is to be properly prepared. I use this handy guide to tell me what I need to wear. By going outside and running daily, I've actually lost almost 50 pounds. If for some reason this doesn't work for you, then you should most definitely use a treadmill.
It's quite common for households to have a treadmill in the basement. It all depends on the fitness levels of your family. If you're dreading getting back into shape and spend a lot of time in front of the computer, then a good way of hacking yourself back into shape is converting your treadmill to a walking desk. Former Secretary of Defense Donald Rumsfeld swears by standing desks and it's well known that sitting for hours a day in front of a computer isn't healthy.
Midnightmonster conveniently built this treadmill desk using a treadmill, some pieces from an IKEA Jerker desk, as well as well as a $30 metal shelf from Costco. The Jerker desk props up his keyboard and mouse, while conveniently being able to prop up his computer as well. The metal shelf serves to mount the computer screen. This hack is quite easy to accomplish. All you need are the right pieces.
[via Gina Trapani]