The Palm portable keyboard is a solution designed for Palm Pilot. Simply unfold the keyboard, much like an accordion, and plug it into your Palm for smooth typing on a full-sized keyboard only missing the numerical pad on the right (which is found on most PCs). Closed, it’s 3.6x 5.1x 0.79 inches and opened up it’s 13.8x 5.1x 0.3 inches. It weighs only 7.9 ounces and its US list price is $99.

The Palm portable keyboard (manufactured by Think Outside) arrives with a fully padded zippered case and comes with a built in docking station that requires no batteries or power supply since it draws minimal power from your Palm. A recessed connector for the Palm folds neatly underneath the keyboard.
A key setback for the keyboard is that it absolutely requires a flat surface to use. It is virtually impossible to use in your lap. Also, the keys are a bit more cramped in the portable keyboard as opposed to the average PC.
The keyboard comes with an application that acts as a driver and makes the keyboard work exactly the way the user wants. When the Palm is plugged in, the user can immediately begin typing. When the user removes it and plugs something else in, the keyboard driver doesn’t interfere.

The Palm portable keyboard is designed for people who use their Palm like they use a laptop. Paired with the fact that users are pretty much assured that it will continue to be useful for several future generations of Palm handhelds, stands to make the Palm portable keyboard a great purchase.

The MuMoH physical collection includes a functioning keyboard, serial no. P10713U.

References:
http://www.pdacortex.com/palm_portable_keyboard_review.htm
http://www.palminfocenter.com/news/2009/review-palm-portable-keyboard-for-m500-series/
http://www.dansdata.com/portkey.htm