The story behind Facebook's real-time notification system

A few weeks ago, Facebook rolled out a new real-time commenting feature. But what the average user doesn’t realize is that it took some serious manpower to get the real-time commenting system right.

FourSquare adds photos and comments to check-ins

FourSquare yesterday updated its iPhone application to allow users to post photos and comments when checking in - and says it's already getting one photo upload a second.