A classic office tool for information transfer is email. Modeled after the postal-mail people in offices around the world (and at home, at the beach, around the campfire etc.) send notes and other information snippets to other co-workers. However, email has fallen to prey to the same albatross as its physical cousin; how to discern what is important and what is not-so-important.  There are classic methods for determining which stuff is important such as the importance rating (usually some form of !!!!) or possibly treating everything from a particular email address as important. 

The popular Google email service  Gmail introduced a new feature a while ago called priority inbox. The basis for the service is that Gmail pays attention to which emails you read, and reply to in order to infer which emails are important. The system then sets the important messages aside and marks them for immediate review. I have been using the feature for a few weeks and so far the service has done a rather good job deciding which emails are more important than others. It does this by understanding which email messages we open and which we respond to etc. 

However, the greater facet to this development is that it turns email from an information delivery system to an information ranking system. The system already pays attention to which messages we read (which is a de-facto importance ranking unto itself) the next step is to deepen the relationship between the content and the ruleset.