Rebecca, at 14 months, has just crossed a threshold where she is able to work on shape matching games now. She has a wooden puzzle with a big circle, square, and triangle with nice big handles that you can pull out and put back in their holes. Previously, she could get the circle in and out, because it will go in no matter how it is twisted, but never had any luck with the square or triangle. Now she has crossed some cognitive boundary where she sort of realizes she has to twist the pieces to fit them in, and is beginning to experiment with what piece goes in what hole. Similarly she has a couple shape sorting boxes that she is also starting to use. She knows that the blue ball goes in the circular hole, that's the easy one, and can get some of the other in depending on how she is holding them - the cylindrical heart is the hardest because it only goes in two ways, whereas the cube can be rotated lots of ways and still go in. The plastic shapes with really rounded edges are much easier to twist in than the nicer wooden pieces that have really square corners, unfortunately for esthetics.
She also seems to be getting more interested in crayons, and she is still interested in putting things in containers and pulling them out, and putting lids on things. Another chief amusement is pushing the music buttons on her busybox and then dancing. It is really cute when she starts dancing.