You can't complain that your cat ends up in another persons house when you allow it to roam wherever it wants, cats go into other peoples houses regardless of encouragement. The only workable solution is to be responsible and confine your animals to your property.
Cat's are not like dogs - with a few exceptions, their natural habitat is outdoors. Cats have always straddled the line between domesticated animal and wild animal.
You know it makes sense.[/QUOTE]
But will it get through their cat flap. :D

The only logical solution here is to get a dog.