Most used are these green character displays with two or more rows to display menus, status or debug messages. With mass production of mobile phones, color LCDs get that cheap, that they can be used as replacement. To test the display, I hacked a kind of small digital picture frame, that fetches pictures from Flickr.

The Nokia 6100 display is able to display 130 by 130 pixels with 8-bit or 12-bit color (4096 colors) and it has a LED backlight. It is controlled with Serial Peripheral Interface Bus (SPI). That means it needs only 3 wires for controlling it. To control the display author has used an ATmega48.

Flickr on Nokia 6100 Color LCD