Tablet PCs

Does anyone (besides Sir F. Crisp, with whom I have been consulting a bit) use a Tablet PC regularly, either personally or professionally? I'd love to hear about it. I'm thinking of getting one. It seems like it would be perfect for working on, especially in combination with Microsoft OneNote.

OneNote, by the way, is probably about the closest I'd ever come on a Windows machine to my all-time favorite piece of software, Circus Ponies Notebook.