I got a new keyboard, the Logitech TypeAway, for my Palm M500. The old one, the Ultra-Thin folding keyboard was gradually becoming less responsive, so it was time to replace it. Fewer keys seemed to work each time. So that's no good.
I liked the Ultra-Thin very much, but the fact that one failed made me hesitant to get another of the same.
I generally like Logitech devices, so that's what I chose. It was new in the package, from EBay. Though of course the keyboard is 20-some years old, just unused.
The Logitech Typeaway is nice. It took a little fiddling to get it set up. In case you are wondering, you have to uninstall any old keyboard program and install the new one, then hit the reset button to restart the Palm, before it will register. The keyboard itself feels well made, but it is pretty small. It has a funky split down the middle where the hinge is, which feels a bit funny. I can type reasonably well on it, but some of the buttons are pretty small. I have medium-large sized girl hands. If you have larger hands or thicker fingers it would likely be too small to be very fun to use.
But what's great is the small folding size, so it's very portable. It does not require its own battery, so that's even better.
If you need to download the driver for the TypeAway, you can do so here: https://palmdb.net/app/logitech-typeaway-keyboard-driver