If you haven't already, you've got to give OneNote a whirl http://www.microsoft.com/office/onenote/prodinfo/trial.mspx.  I'm not the most organized guy on the planet (big surprise), so I love the free-form entry and search capability.  I don't have a TabletPC (yet), but I still find OneNote to be a superior note-taking tool.  I'd love to see the product team add some mind-mapping functionality (http://www.innovationtools.com/resources/mindmapping.asp) and perhaps some tie-ins with Visio Shapes (that snapped-to my meager attempts to free-hand draw architecture diagrams).