Here courtesy of Justin Taylor is a fascinating discussion of the concept of multi-site churches between Mark Dever, Mark Driscoll and James MacDonald.
I have been an advocate of multi-site ministry for several years since I first heard that such a thing existed. The potential to have five thousand or more 20 person congregations excites me greatly. Ever since I read Prey, the idea of the church as distributed intelligence has been the uppermost metaphor in my mind.
I see Matthew 13:33 and I think of 5000 or more 20 person congregations gathered around living rooms being the church in the world leavening the whole lump instead of concentrating in one ginormous air pocket and ruining the bread. the goal of church never has been, is not and should never be to see how many people we can cram into one room for an hour or two on one day of the week.