Most artificial islands are used for tourism and recreational purposes. However, as cities continue to grow and land becomes increasingly scarce, artificial islands are being built to mediate this problem.  Recently many cities have begun builidng airports on artificial islands, in order to maximize land use in the city. 

Currently there are a number of airports that have been built or are being built on artificial islands, with most concentrated in Asia. One of the largest is Hong Kong International Airport. Located off the coast of Lantau Island the airport handles 47,783,000 passangers a year.  

The first artificial island airport was Kansai International Airport in Japan, which was the first built in 1994.  Newer artificial island airports include, Ch?bu Centrair International Airport in 2005 and the New Kitakyushu Airport and Kobe Airport in 2006.

I think as cities become more heavily populated we are going to see more aritificial islands being built off the coast of cities. I am sure their use will be quite diverse, ranging from industry and manufacturing, to transportation and recreation. The future is certainly exciting for island development.