Naked DS

EDN has this excellent piece on dissecting a Nintendo DS, and then commenting on it's naughty bits in both overtly geeky ways and in layman's words on what it all means:

The lower display also includes a touch-sensitive overlay driven by a Texas Instruments TSC2046 Touch Screen Controller IC, which is mounted on the rear of the main pc board, just under the flex-circuit connector. Players can drive the lower screen with a stylus or their finger. Nintendo's engineers also devised a plastic nib, connected via a strap, that players can wear on their thumb to operate the touchscreen interface.

The combination of dual displays and touch input would seem like a big win for Nintendo. The dual displays support many new game modes. For instance, a player could use the lower screen for navigation in a first-person-shooter game while the action takes place on the upper screen.