I can finally re-launch my site (softly), which now focuses on social interaction design entirely. I also have a slideshow that introduces, with the brevity forced by use of bullets, the concepts of social interaction design. I’ll be posting several more in the week to come on specific aspects of user psychology, web 2.0 applications and how they structure social practices, and case studies/examples.
Have a look if the topic interests you, and I’d love feedback!
On slideshare: http://www.slideshare.net/gravity7/what-is-social-interaction-design/