The science is in! Research shows that sitting all day is no good for us. Sitting for prolongued period of time can lead to neck, shoulder & back pain, leg cramps, scaitic issues and more.

This is because sitting isn't a natural position; we're all cramped up when we sit. But it's everything in moderation - you don't want to stand for 8+ hours either. Alternating between positions is the key and our adjustable height desk allows you to easily do that.
I have personally used a stand-up desk for months now and I can attest that it helps my neck greatly, even the eye issues I was having. I suspect the two were connected, that the neck issues would get so bad they would go up into my jaw and eye and cause so much pain that I couldn't be productive any longer.
Well, using an adjustable height desk has greatly reduced those problems. I no longer have nearly as many neck or eye issues as I used to. Plus I just feel better and more productive throughout the workday! When you work at a stand-up desk you move around a little bit, helping you to burn calories and get in better shape.
I also find that it makes me more prone to walk over to a coworkers desk. I'm already standing so getting up isn't a big deal. It encourages more interaction between team members. IM and email is great but sometimes there's nothing like a real world, interpersonal chat. 
Also, if you're on the phone providing tech support, service or something else that lasts a long time, you can pace around. This again helps burn calories but also gives you more energy and something to do while on those long calls. Some people get a wireless headset that lets them go anywhere in their office. Some people working from a home office can do chores while on a call.
Standing up at a desk will also firm up those calves and give you great definition in them. Check out our posts on NEAT exercises - they're basically exercises that you do during the course of the day that don't seem like exercising, like standing up, going up stairs, walking to your car, etc.
Not only does working at a stand-up desk offer all of these advantages, but at the end of the day you can finally feel good about taking a load off and sitting for a while. On your commute home you can take pride in a productive day, a job well done AND you feel like physically did something. Sitting becomes a justified reward. Watching a few hours of TV on the couch doesn't feel like a loser, lazy activity!
For these reasons and many more, we certainly do advocate the use of an adjustable height desk!