I can't say enough good things about this Outlook plugin. I even demoed it to the Windows Search v4 team at the Microsoft MVP Summit a few weeks ago and told them,
"Make Windows Search do this!"
Originally introduced to me by my manager and another coworker, Xobni is finally available to everyone to
download and install.
If you tried Xobni in the past and had performance problems in Outlook afterwards, that bug was fixed a few builds ago. If you don't know what
Xobni is, read the press release
here.
It is actually one of the only add-ins I use in Outlook. I normally avoid them. I love the analytics built into the interface and how it can pull phone numbers out of e-mail messages. I also like the fact that it keeps track of file attachments I have sent and received, per person.
Fun fact: Bill Gates
uses it.
Note: This isn't a paid endorsement, but if they want to send me some coin, I'll gladly accept it.