I have a "Cool Living Stand Up Desk" at home that I bought on Woot a couple of years ago. Note that it's a hand cranked height adjustment. Currently going for $220 on Amazon, but the slow adjustment process is an annoying barrier to switching positions and keeps me from doing it as often as I'd like to.

https://www.amazon.com/Cool-Living-Stand-Up-Desk-Black/dp/B0...

I'm otherwise pretty happy with it, but it's my home desk not my work one. If you're looking for a desk to use for full time work I'd recommend an electric or something with a counterweight or spring system to allow easier changes between sitting and standing.

I've been using this setup for the last three-ish years, and it works great.

http://iamnotaprogrammer.com/Ikea-Standing-desk-for-22-dolla...

I built something very similar too. My setup is to have two screens, one for standing, one for sitting (and two set of input devices). I close one screen when I'm using the other and I mirror the image on both screens.

I have another setup with an Ergotron Workfit (can be lifted up and down) but I find that the position is more adjustable with my mirror-screen version. With the Ergotron the position of the hands relative to screen is fixed so eye-screen distance can't be adjusted as well as I'd like. Also screen height doesn't go as high as I'd like.