I used two trailer jacks to make an adjustable height work bench. I needed a way to store my new X-Carve CNC machine when not in use. You could modify this design easily to make an adjustable height standing desk.
It consists of a Neoprene sleeve with ice blanket from KEGLove, a 12 oz. Paintball tank system using Williams Brewing Paintball Conversion kit, and Quick Disconnect Faucet Adapter from Austin Homebrew Supply.