A clone of www.facebook.com.
I would prefer a Linux, Apache, Mysql, Php configuration, however if there are better existing solutions on different platforms using different languages I am open to that.
The clone must be a copy of all of FaceBook's current features(news feed, notes, mini-feed, events) including, for our own administration, a Site Administrator.
If you already have the clone/script/a web site working, please provide links to a working demo.