I wanted to try a standing desk on the cheap. I checked out all the suggestions I could find, including various Ikea desks and custom builds from Ikea parts. I ended up using a $10.97 plastic 4-tier shelving unit from Wal-Mart.

It was just the right height, snapped together in 2 minutes, and the top shelf is just wide enough for my laptop and a glass of water. It stands right next to my normal desk so I can choose which I want to use.