I actually own two of these, and I bought a third for my mom.
I purchased one of these to go under my desk at work, and I use it almost every day.  Then I got another to use in front of the television.  If I'm going to sit there, I might as well burn a few calories.  :)  You can also use it with just arms, which is actually quite a workout.<br /><br />I'd give it five stars, except for one thing.  The little rubber feet rotate sometimes, and that makes it slide.  I have to readjust one of the feet every time I use it.  Not a big deal, but a little annoying, since they really don't need to move at all, and could have just been glued in place.
Rating: 4 stars