Between 10 and 11 months, he could take 3-4 steps at a time before falling down, and mostly only tried to walk when crossing a short space between the couch and a person or something else close.
Between 11 and 12 months, he started to take a few more steps at a time, could re-adjust and keep from falling down (some of the time!), and started walking out into the middle of the room or standing up in the middle of the room to walk without a particular goal in mind other than walking.
Today, I would say he is definitely a walker, despite the fact that he falls down a lot, but it is hard to pinpoint when I would say it happened. :) Here is a video of him walking around his toys this morning.












