Here is a portable sit-to-stand monitor arm that can be used to turn any desk into a standing desk. It can raise your laptop, monitor, or keyboard up to 15 inches and adjust them 360 degrees. The Maxtand can hold up to 40kg of weight. With 3 adjustable pivot points, you get 18+ positions to choose from.
The Maxtand has a solid aerograde aluminum alloy construction. You can go from sitting to standing in seconds.