Anyone with a museum of rare Apple antiquities should head over to eBay, where an extremely rare Siemens NotePhone is on sale. As noted by the seller "yennyman," the NotePhone was sold in Europe in 1994 for a very short time.
The NotePhone was essentially a modular speakerphone for office use that contained a fax modem and a Newton MessagePad 100 for taking notes, entering appointments and prepping faxed notes for sending. The Newton has the Siemens brand on it, not the familiar Apple logo. At the time the NotePhone was introduced, the price tag was around DM2,400 -- about US$1,000. There was apparently a prototype based on the MessagePad 2000/2100 that appeared a few years later, but there's no sign that the newer model ever made it to market.
If you're interested in acquiring this awesome device for your museum, you'd better hurry. The last time one of these showed up on eBay was apparently in 2004. It will also be important for you to speak German, as the Newton is localized for the German language. At the time of publication, there were two bids, with the top price so far at $202.50.
Thanks to Jens for the tip!