At work I'm currently using an Ergotron. It's pretty amazing for switching up my desk routine, considering I'm at it for several hours a day.
I will say, however, that I do often forget to even use it! haha!
Honestly, they're quite expensive. Unless you have a business income that is sufficient to buy you one, I'd recommend just taking a few minutes an hour every hour to just stand and stretch. That's free. 
