Correction : You said it belonged to a neighbor. THAT's NOT PUBLIC! Booting up and having an unsecured network connection in your area doesn't mean it's free for you to use.
Right now i have 6 available wireless entwrok i COULD connect to in my neighborhood. From my desktop i can see all of them. Does that mean they are free for me to use? I'm not hacking, Windows jsut has them displayed as unsecured and in my area like any other connection.
To connect and use someone else's wireless connection without gaining the permission first of the original owner of that connnection is flat out ILLEGAL.