The idea isn't so far-fetched. Some cities have a community of free wifi hot spots (mine does) and churches could be a part of that landscape, and as far as community services that don't require opening the building, it is far more pleasant than serving as a dog toilet.
TallSkinnyKiwi blogged about this a year ago from his experience in a Japanese church, and points out some practical pros and cons.
But the church with a WiFi zone I like the look of is Fellowship Church, of Grapevine, Texas. (Any visitors over the Fort Worth General Assembly?) Actually, there are a lot of "user-friendlinesses"I like about this church, including its cafe, hip-kitch style, and downloads for which might otherwise be a garden-variety Evangelical church.