I found these:
http://www.roalan.com/Bluetooth%20Wi...0Converter.htm

Hmmm... I'm wondering now: With one of those and the battery adapter, would I be able to turn my Newton serial keyboard into a Bluetooth Newton keyboard? The scancodes for the Newton keyboard are on the Net (somewhere on the Net...) and a converter from Mac serial to RS-232 is not exactly rocket science (I've made a few already).

I have to admit that I do like that clickety-clackety Newton keyboard very much; it's very nice to type on. It's of course a very anti-social keyboard in quiet environments, but I consider that a plus.

Thinking about it: I might buy the pair, and give my poor SIMpad a bit of Bluetooth.