Oh. My. God.
Why didn't anyone tell me dogs don't understand english?
I brought him home, took him to the back yard, and followed UT's advice. That seemed to work very well, we have not had one accident yet. I spent about 45 minutes helping him explore, and once I was confident I had blocked all escape routes, I went inside to get him a water bowl. Time elapsed from leaving the backyard to return with a water bowl could not have been more than 3 minutes. He lived up to his name to astounding effect. I still have no idea how he got out.
We found him after hunting the neighbourhood, playing with the kids down the street. I have one of those long leashes in the yard now, hopefully situated where he can't get tangled. Famous last words.
I have taught him to sit, but only when he is abso-fucking-lutely certain there is a treat in my hand, and he loves to howl, despite the repeated assurances of his former owner, my so-called-friend.
But on the other hand... He is a very sweet, affectionate dog. He loves my son, and he only howls when he can't see one of us. He loves to play, and the way he lies on the floor, with his back legs splayed out, is the cutest thing ever.
Its going to take a while, I think, to teach him what to do and when to do it. But I suspect its more about teaching him to trust me than teaching him to obey me. He had the run of the house with the previous owner, and I think he might just be rebelling against the more "structured" environment of his new home.
Ugh. Its gonna be a long month.