Google have rolled out a beta trial of its Priority Inbox service for GMail. Essentially, it allows you to flag which emails are important and these then are shown at the top of your priority inbox. Starred emails appear next, and then all the regular stuff appears after that. This is quite a useful feature and very easy to set up (unlike some other google products I could mention). I'll be using the Gmail PI for a few weeks to assess how good it is at identifying important email.

The video below demonstrates some of the PI's main features: