His latest expoit is to take a few steps in the courtyard (concrete tiles) very cautiously (he did not fall). In the afternoon and evenings, he goes up and down the (carpeted) hallway and elevator lobby on our floor (pre-childproofed! other than the neighbor's plant). He took a small wooden ball with him one day, and started moving it along the ground by walking over it (missing sometimes, obviously -- it's small). The first few times, we weren't sure this was intentional. No uncertainty now.
R. brought out a larger ball (very lightweight structure like a soccer ball, but like a hollow outline -- a wireframe diagram of a soccer ball, but made of plastic of some kind). This was much easier to move along the floor, and it was more obvious that he was specifically kicking it, rather than just walking over it.
And he's been watching some of the world cup exhibition games. Does this make me a soccer mom? It just seems way too early.