Walking!
Yes, Theodore has started walking! He is very pleased with himself and we are thrilled too, obviously. He was taking 2-4 independent steps two weeks ago, and then last Saturday he just took off with Billy at the park. In the week since he's become very confident, walking far distances and turning well, and he can also stand up without needing to pull up on anything.
Here's a video I took of him walking last night. I'll post a longer update sometime soon!