Why not lock your wireless network adapters down so that they do not attempt to connect to unsecured networks?
You may by your actions anger your neighbor. A wireless network that does not use WEP or WAP may not be wise from a security standpoint, but is not breaking any laws. And surveys have always suggested they are in the majority of installations -- some on purpose, some due to ignorance.
And, there are many community WISPs where they are deliberately set without security.
There is no reason for these unsecured networks to affect your connection to a secured network. You should be able to specify in your client adapter settings that only secured networks will be used, and to set the priority for the identified networks in their order of connection.