I was never really into the Newton, but I hadn't realized they made a combination phone device like this Siemens NotePhone (probably because it was Europe-only). Not only did the NotePhone have a 336 x 240 screen (still decent), the unit added telephony and voice mail to the Newton itself, which could also be removed and used seperately. This auction is over, but there weren't any bids, so I bet you could still pick it up if you wanted to.
His starting bid was $365 (!), but they apparently used to sell for over a grand.