xD-Picture Card
The xD-Picture Card, a type of flash memory card, was used in a more limited selection of electronic devices, including digital cameras. Olympus and Fujifilm were the two brands of devices to use the xD-Picture card. It had a capacity of up to 512MB for the original version, up to 2GB for the Type H and M/M+ versions, and it has physical dimensions of 20mm x 25mm x 1.78mm.
As of 2010, it was considered obsolete, but it is still produced today.
Also see: Memory cards, Memory definitions