The importance of counties in the US does indeed depend upon what part of the US you;re talking about. In most of the states, the county is the primary subdivision of the state. (Louisiana calls them parishes, but they're counties by another name.) In the Northeast US, however, counties are less important, because smaller subdivisions are more important. In New England, towns (equivalent to townships in the MidAtlantic and Rust-Belt states), take over in importance. In Maine, the county has a role in jurisdiction over the minor civil divisions that lack population (many "townships" in Maine have a population of zero), and counties help out by providing some services in Vermont and New Hampshire. In Massachusetts, counties are a fairly weak agglomerations of towns, and in Connecitcut and Rhone Island, the county governments were abolished and there exist only as historical remnants, or as a collection of towns when folks at the federal level want to compare things county by county. That's why there aren't county seats there--there's nothing to be seat of.

Canada had counties only in southern Ontario, Southern Quebec, PEI, New Brunswick and Nova Scotia. Ontario merged counties in recent years, probably contributing to their weakening as geographic areas one might be loyal to, and Quebec kept rearranging borders, and i believe has abolished counties.

A good resource on local governments in the United States may be found at http://www.thegreenpapers.com/slg/cd.phtml

--Charlie Baum, originally from the town of Trumbull in Connecticut, now resident of Montgomery County in Maryland