One of the trend this year or decade now is social network...the social network is answer from many question how to connect many peoples from many different places and different jobs or social status..
Social network is good clue for that questions..
Many developer of site compete to do many variations related social facebook plus many features and applications to attract many people as their members,,,
Facebook lead social network site to attract many peoples..
facebook do know exactly whats the needs of everyone..Eveyone needs to reunion again with their old friends or get many new friends..
thats wonderful i think