I'm a big fan of Hugh MacLeod's Gaping Void blog and his wonderful cartoons which he now draws on a Tablet PC. Recently he appeared on the Gillmor Gang podcast and among many things discussed on that rambling show he talked a bit about using his Tablet PC to do his cartoons. (He now publishes more of them on his blog than he did before using the Tablet PC.)
The Tablet PC info is on the long podcast around the 16 minute mark. There's lots of other fun talk about the cartoons and blogging in general. Check it out here.