Cybiko
A key feature of this portable handheld was messaging. It had a keyboard and you could send messages directly to any other devices within radio range. You could also relay messages via another Cybiko into an Internet gateway.
I have fond memories of the Cybiko handheld computer. Originally priced at $200, and eventually being available for less than $70 (in quantity), the Cybiko was a PDA designed for teens and tweens. It was my first introduction to serious programming, and I programmed for it in CyBASIC, C, and B2C (a BASIC-to-C converter created by Greg Smith).
It particularly reminds me of olpc because it had mesh networking capability (900 MHz band) over which you could send messages, transfer files, and play games wirelessly. There was also a web browser created by the 3rd-party Community. Furthermore, the device has a full QWERTY keyboard and directional arrows that can be used for controlling a cursor. It was released in 2000; I got one in 2001 for $130; I worked on it for about two to three years. I was also the Administrator of the most popular Cybiko Forums.
Like the XO, the Cybiko had even more limited hardware capabilities. Very slow processor, little RAM, little Flash memory. It did have a directional pad and some gamepad buttons, like the XO. The second model, the Cybiko Xtreme, had a built-in microphone and speaker.
The Cybiko was the One Laptop for me and my childhood. It changed my life for the better. It serves as an example of how I know OLPC can definitely become a reality for many kids around the world.
Elliot Lee http://www.intelliot.com/blog/
Here is a review with photo from when the Cybiko had recently been introduced. https://web.archive.org/web/20110703195923/http://www.streettech.com/archives_gadget/cybiko.html
This is the Cybiko developer site where you can see the kind of applications that people have built targetted to the same age group as the OLPC http://www.devrs.com/cybiko/
This review of the UK model focused on the messaging features http://www.compulink.co.uk/~davedorn/reviews/hard/peripherals/cybiko.htm
On Wikipedia here