http://groups.yahoo.com/group/melbourneinternationalsocialgroup/
This group will hold monthly social functions (for singles, couples, anyone!) for expats or repats to Melbourne. The first group of its type in Melbourne, it welcomes people from all over the world now living in Melbourne (including returned Australians) to meet, share stories, have fun and enjoy a drink together.
Just visit the above link to join, it is free.