I've been trying out using a standing desk arrangement for a week so far and I thought I'd make a note as to how it's gone.
I already had a desk on Ikea trestles, so jacked that up to the maximum height - 92cm - and placed the 15" Macbook Pro on a small wooden set of drawers - 15cm tall, Ikea again. A second 22" screen sits to the left on another wooden unit.
Both screens get angled upwards a bit, and the Wacom tablet is lower, to the right, about 8cm off the desk on a solid binder, so angled up a bit. I have a solid toolbox in front of me to raise a foot onto, as a stool when sitting too. Cost = zero. Your costs may vary.
I work like this for about half the day, on and off. I tend to move the laptop down onto the desk and pull up a Steelcase Leap chair at maximum height for some things, and seem to do more of the standing before 2pm and more sitting later on.
I always get an hour out walking the dog between 2 and 3pm. So far, it's quite good although I'm not sure I can make any great claims for increased attention or a massive surge in energy.
It does definitely feel better than sitting all day long, especially if in the evening you might watch TV, read or play games. I wrote this standing up, and although it's 4pm now, the dozy feeling of late afternoon is kept at bay. I will report back in a month.