Finding a Dog

Yesterday, my wife and I were talking about getting a dog.  We are going on vacation in August on two different weeks so we want to get a dog in September.

We were talking about going to the Humane League and then were wondering if there was some kind of Craigslist category for pet owners moving to a new town who can't take their dog.  I know when an Army unit moves out for a large deployment or relocation, there is a scramble to find homes for pets.

If anyone knows of a list like that where we could give a home to a dog that needs a home, let me know.  We are looking for a medium-size to large dog.  Definitely a dog who likes kids.