I’ve occasionally been encountering the new features introduced in OS X Mountain Lion. Late last week, I noticed that when I hovered over the sender’s name in an email message, the light-gray outline of a star appeared. I assumed this must be a mechanism by which to mark a person as a favorite and was immediately intrigued to find out how favorites would manifest across the application. As soon as I marked one, the star became a persistent indicator beside the name, and a new category was added to my Mailboxes sidebar: VIPs. Upon expanding the VIPs category, the person whom I starred was listed. I now had instant access to every email to and from my boss, regardless of where it had been filed. Furthermore, unread messages now displayed a filled star (rather than just the outline). It’s a relatively simple addition, but it is supremely useful.
This is an excellent example of taking a concept that has proved popular in certain situations and adapting it to improve longstanding models of interaction. It illustrates the power of “What if…?”.