Designing Social Interfaces: Overview and Practical Techniques

I think article this may be too sparse in details for a subject that so important.

For better resources, please see:

http://www.bokardo.com - for design of social interfaces (please read everything you can, it's not that much)

and

http://buildingreputation.com/doku.php?id=bryce (for reputation systems. Bryce is the man here.)