This things are 65€, and can be used by an arduino or anything having RX/TX:
They feature an audio amplifier,  micro-sd storage for images/wav files/scrips, and a rather high-level set of drawing routines (lines, rectangles, text at position), resistive touch screen. COLOR.
The ultimate Ultipanel of the future?
The ultimate interface for my new Coffee-Machine hack?
lets find out...