What's funny is that palm got sued by Pilot pens for using the name Palm Pilot in their early days.
So it would seem there has been quite a bit of confusion over the names of these little devices.
PalmPC was obviously a rip off, but I think that Palm Pilot had little to do with pens. Sure they have stylii, but in this case I think they were going for palm 'control' not palm 'pen'.