Although Canada is still the US' largest trading partner, Mexico is now the US' biggest international phone call partner. According to email from Brian, for which I can't find the source, Mexico accounted for 5,193.1 million minutes in 2001, and Canada for 5,105.9. That wasn't the case before 2001: "According to the Federal Communications Commission, Mexico is the second most frequently called international destination by consumers, and receives 14.3 percent of all international call traffic from the United States. The most frequently called country is Canada and receives 15.2 percent of total U.S. international call traffic." (ref). Here's a good article on "telegeography".

Canada is not yet supplanted as largest trading partner because in 2000 Canada traded with US to the tune of US$411 billion, while Mexico accounts for US$261.7 billion , the next largest (ref 1, 2). However, if Canada/US trade continues to grow at 7-8%, and Mexico/US trade at 25 - 30%, Mexico will be the largest trading partner in 2004.