Digital devices are getting smaller and smaller, and we're sure this trend will continue. As a matter of fact that the SD memory card has become a great solution to our life. At an amazing 24mm wide, 32mm long, and just 2.1mm thick, the SD memory card will not fail its design in terms of its function. Small size alone is not enough, though. Large capacity is essential for adapting to a variety of digital content types. SD memory cards are currently available in a 1GB size which can hold 9 hours of digital video (MPEG4) playing. Other capacities available include 128MB, 256MB, 512MB, 1GB, and 2GB.