As we set off to take our dogs for a walk down the Highline Canal this morning, we ran into this hound dog coming towards us in the opposite direction. He has a collar, but no tags. He's friendly and well-fed, and (surprisingly for this neighborhood) a neutered male. We've put him in our front yard and given him water, and put his photo up on Pets911.com. With any luck, his owners are somewhere nearby. (If they're close enough, they should be hearing his distinctive hound bark...)
UPDATE (1:30 p.m.): His owner put a "lost dog" ad on azcentral.com that we just found, and came and got him. He normally has tags, but they came off when he got out about a week ago.