Ok Judy Cavegirl... check out the Intentional Communities website at
www.ic.org. I've been browsing through this, and it turns out there are
hundreds of them. Some of them are quite amazing and very advanced like
Damanhur in Italy, and the proposed Elusian in California, and others run the
gamut.
There must be a paleo one in there somewhere...I'm going to keep looking!

Also the cohousing idea that Paula posted is worth looking into as well.
That's an interesting website.

Charles
San Diego, CA