DD took her first steps at 26 weeks old and by 10 months was climbing over baby gates and running up and down stairs. She has several scars to prove it and for months we had no hard furniture in the living room (forget about baby proofing, we just stripped the room). She rarely wanted to ride anywhere in a stroller or pack... she wanted to walk/run/gambol/bolt/scamper/climb. So we found her sturdy boots (thank goodness her feet were huge because most shoes for that age were not meant to actually hike in) and a baby leash. This was an absolute requirement just to keep her from getting killed.
There were many long hikes, playing in gyms and bouncy house places, etc. As she got older, we got better at judging what she could do safely that other kids couldn't (like climbing to the top of the play structure and balancing on one leg*) and places we really had to watch her.
* We have a great photo of her at just around nine months old, standing on one foot in my husband cupped hand, arm outstretched. It was adorable, but freakish.
