The Nubli add-in for Outlook:
Nubli is a new add-in for Outlook that allows you to process and organise your inbox in a smart and quick way. It automatically analyses your emailing history and sets priorities and groups your emails in priority sets. You can also customize these priorities and prioritize your contacts. All this a lot more features, like marking emails with actions items and reminders, can be done at the click of a button in the Nubli toolbar.
Download your free trial for Outlook 2003, or Outlook 2007, here.