I came across this amazing image the other day. It shows a map of friendships taken from a sample of around 10 million. Each line represents the number of friendships that exist between the two places it connects. The brighter the line, the more friendships exist. Whilst the extent to which the data reproduces in detail the outline of landmasses and the location of cities is startling, it is also sobering to note the absence of many prominent areas of the world. A high resolution image can be seen here.