[quote="Joan_M, post:3, topic:217925"]
I disagree. The Amish, for instance, isolate themselves from the mainstream community. It is our calling to live in the world while being not of this world. That is how we can leaven the world and give good example.
Christians are not called to live in ghettos, isolating themselves from day-to-day dealings with the rest of humanity.
They don't isolate themselves as much as you might think they do. We have a small Amish community just a few miles up the road from where we live, but they shop and eat at many of the same places we do. They are very friendly with their neighbors, its not uncommon to see them at neighborhood picnics, I've even seen them at Catholic funerals if one of their friends is Catholic and has passed away. They help out on the farms and work with many of the construction companies around our area as well. They use the public trasportation sometimes. They are very approachable, their community isn't really that much different from what the OP is proposing for Catholics.
Edited to add: technically its not a strict Catholic community, but this might be of interest
I don't think they can legally restrict their residents to just Catholics, but it is right next to Ave Maria University and they do have a parochial school already within the community.