Everything 100% clientside (jQuery + JSON API's), hosted on Amazon Cloudfront, in other words pretty scalable.
Screenshots:
Newsfeed: http://i.imgur.com/oyEdm.jpg
My own wall: http://i.imgur.com/iUAsq.jpg
Photo albums: http://i.imgur.com/iIDKa.jpg
Search for 'Joyce': http://i.imgur.com/6I104.jpg
