Note from an old friend who lived in Tonga for several years [and who is returning: I had heard about Tonga, that South Seas island group that was known for its beautiful people and beautiful shores.

A record number of people in the U.S. now live by themselves -- and they spend $1.9 trillion a year. Businesses are beginning to take notice.By Eric Klinenberg, contributorFORTUNE -- In 1957, Universi