I bought a shield with a touch screen some time ago. 261120303957 @ebay http://forum.arduino.cc/index.php?topic=134708.0
I lost interest because I couldn't get the SD card working but now I wanted to play with it again.
I know that the graphics were working once. I shows a demo of what can be done. Now I have one Ardunino were it worked. I have a Leonardo were the screen stays white but it looks that the the graphics demo started but the display went white after 0.5 sec. And ein have a different Ardunio clone which I now think is toast because it doesn't react anymore and it got super-hot within 5 sec. I always used an extra PSU.
I really would like to get it running with the Leonardo.