stacking blocks

Vaughn and I were playing with his blocks today. He can stack 6 blocks now, last time we tried it, he could only do 3! I was stacking blocks too, and I had about 18 stacked before they fell over! One of them flew all the way across the living room and Vaughn thought it was so funny!!!! Of course, he had to go get it right away, so it wouldn't get lost... When we were done playing, I told him we had to put the blocks away, and he picked them all up and put them in the bag!!! He's really good about putting things away-- I hope he stays that way!!! LOL