This article is from the Ergonomics and Typing Injury FAQ, by Dan Wallach email@example.com with numerous contributions by others.
Apple Computer, Inc.
Sales offices all over the place.
$119 (some dealers have it for less)
Apple's keyboard has one section for each hand, and the sections rotate
backward on a hinge. The sections do not tilt upward. The keys are
arranged in a normal QWERTY fashion.
The main foldable keyboard resembles a normal Apple Keyboard. A separate
keypad contains all the extended key functions.
The keyboard also comes with matching wrist rests, which are not directly
attachable to the keyboard.
Many peripheral keys, such as function keys, are "chicklet" keys, rather
than full size, normal keyboard keys.
(See the files apple-press and apple-tidbits on the ftp.csua.berkeley.edu
archive for more details)
Unfortunately, Apple has apparently decided to discontinue this keyboard.
They legitimized the industry, and now they're leaving it. C'est la vie.