I use Microsoft Dynamics CRM as my customer relationship manager. It integrates nicely into Outlook, but now I can integrate it into my OneNote as well. Daniel Escapa has provided some links to a new MSDN article by Jeff Cardon and Rachel Drossman covering how to extend Dynamics CRM into OneNote as well as links to the Microsoft Dynamics Snap binaries and source code over on CodePlex. In addition to the OneNote Snap, there are also Snap applications available for InfoPath and other Microsoft applications.
Using this Snap, you can take notes in OneNote Mobile 2007, sync with your Tablet PC running CRM and have it sync into the CRM database and be available to others who use the database. With the OneNote Mobile feature to take snapshots of business cards combines with the CRM Snap, you could have a quick and painless way to add new contacts to your contact database.