The Regions of Mind blog has an interesting post with maps dissecting the distribution of religious adherents in America (full larger versions of all these maps). The real surprise isn't that the south is predominently Baptist (well duh), but that Catholics and Lutherans have such large representations, and we hardly hear about them when anyone talks about the religious right.
One more interesting note. On the map of Prebyterianism, the bright spot in the Virginia mountains is where I'm from. This squares very well with my own experience growing up. All those Scots-Irish immigrants that populated that area where Presbyterian after all. I'm more surprised that Presbyterians make up such a small segment overall (relegated to the other category on the main maps).
NP: "2/4" - Clinic