http://www.youtube.com/watch?v=hhTNTPNs350&eurl=http%3A%2F%2Fvideo.google.com%2Fvideosearch%3Fsource%3Dig%26hl%3Den%26rlz%3D1W1ADBS_en%26q%3Darduino%20gba%20screen%26um%3D1%26ie%3DUTF-8%26sa%3DN%26tab%3Dwv&feature=player_embedded
This could be a fun thing to do!
I got a nds touchscreen from sparkfun today.