Finally, Carter stood by himself for 3 full seconds last night. I had to get him balanced and let go, but he did it and we clapped and cheered and he was very proud of himself. We'll keep practicing and I'm sure by next week he'll be a pro.
Another thing we've noticed him doing is that he pushes a ball, toy, whatever in front of him so he can chase it. He'll take the back of his hand and push it. He's like a kitten.