Nintendo is to roll out a camera specifically for use with the DS/Lite in Japan on August 2nd. The first piece of software to use it is Otona no DS Kao Training (Adults' DS Face Training.) In fact, the camera is called the Facening Scan.
Facening is a regime of facial stretching designed to reduce wrinkles and sagging, and to make your face appear smaller.
The camera slots into the GBA, Slot 2 part of the DS and is included with the software, as is a DS Lite stand.