The OLPC-XO1 is a nifty piece of kit, although its low processing power makes it nearly useless. This little guy has the best wi-fi range of any device I've tested. I acquired it back in 2007 during a "Give one, get one" event. I had some fun replacing the keyboard. It originally featured a rubber membrane keyboard that utilized the stainless chassis as a groundplane. The keyboard is nearly unusable since the force required to press a key is less than what it takes to sense the key with your fingertips. The only way to type on it is by staring and pecking. I saw an instructable where the author hacked in a tiny usb keyboard. The keys on the XO are small, even by child standards, so it was remarkable that there even was one whose physical characteristics were similar. The original keyboard controller is integrated with the mouse controller, so removing it isn't really an option. Adapting the new keyboard to the old controller would require detailed knowledge of both that wasn't available to me. So instead, the instructable author made room for the new keyboard controller recessed between its backplane and the chassis cover, soldered it to the usb controller and called it a day. I followed the instructions pretty much as-is.
Because of the small form factor, the overall improvement was negligible. There is some distortion to the case because the silver cap (visible in the third image) causes an interference fit. I should have relocated it with short pig-tails. They new keyboard isn't much better to type on either. The small form factor precludes touch typing, though the addition of dots on the F and J keys does make homing easier. The backlight control is missing and will have to be bound to keys in software. The other functions appear to simply be bound to function keys. While this mod was fun to do, I can't recommend it to anyone else, it simply isn't worth the trouble.