My desk calendar, supplied by storage vendor EMC, carries the theme of information throughout the year via daily notes and quotes. Today's entry, sourced from a September 2007 Guardian article, reads as follows:

"Although the numbers of friends people have on [social networking] sites can be massive, the actual number of close friends is approximately the same in the face-to-face real world," says psychologist Will Reader from Sheffield Hallam University.

His survey of 200 users of social networking sites found that people tend to have around five close friends.

Some 90 percent of the online friends rated as "close" have been met face-to-face, with the remaining 10 percent likely to be friends of close friends, perceived as having many of the mutual friend's attributes and, therefore "low risk."