Xobni, which is currently available for free on their website, indexes emails in Outlook and make them readily available and searchable for future use.
While other desktop searching clients like Microsoft Desktop Search and Copernic already offer email searching functionalities, Xobni goes further and adds a few more extras.
For example, it can pull phone numbers automatically and create entries for name, it can also thread messages which allows you to follow conversations and provide with precious statistics on the way you communicate with your colleagues and partners.
Bill Gates is known to be using it as a productivity tool and has recently demoed it as part of his opening keynote at the Office Developers Conference in San Jose.
Xobni already has plans to release a corporate version later this year and is rumoured to be working on web-client based plugins for Yahoo mail and possibly Gmail as well.

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