Skype continues to grow but that growth remains limited in the United States. Datamation reports on the issue, quoting Skype VP Don Albert as saying that the U.S. is a last frontier for Skype and that growth will continue. Skype gives some fuzzy numbers about that growth, counting in terms of downloads rather than active users. For numbers that might be more accurate, check out this interview with Jean Mercier, author of the Skype Numerology blog.