In recent days, my little daughter (3y) developed an interest in writing letters on dad's computer keyboard. What better excuse could there be for building a first computer for her!
Luckily, the PICAXE-14M2 micro controller makes it very easy to interface a standard PS/2 keyboard to a serial OLED display.
The current software version does little more than simply echo the key presses on the display while showing a blinking cursor and keeping track of its position on the screen. A future version could be enhanced with custom graphics or even little games. There would still be plenty of room in the processor's memory for this.