The Stansport Camp Stool is 16 Oz. and can be had online for a bit over $20.00 shipped.

http://www.stansport.com/index.php/g-613-s.html

I have a similar stool, but it's not aluminum and weighs 2 Lb. The only problem is that the legs will sink in soft ground and the end caps will come off when you pull the stool out. I drilled a hole through each leg and cap and used a wire tie wrap to secure the end caps.