I've gotten a few emails lately from people who are really impressed this Outlook add-on, which was previously in a closed beta:

It's a whole new look at your email:

Xobni is the Outlook plug-in that saves you time finding email conversations, contacts and attachments.

After a quick install, you'll see the new Xobni toolbar appear in Outlook - and suddenly information will become much easier to find. When a new email arrives, the sender's full communication history appears in the Xobni sidebar, including past conversations, attachments and contact details. Xobni also includes a blazing fast email search tool.

Xobni is "inbox" spelled backwards, BTW.

Downlolad Xobni