Micro SD Card - The Smallest Memory Card:- Derived from SanDisk TransFlash, micro SD cards too are a format for removable flash memory cards. These Cards are currently the smallest memory cards that are commercially available. With a tiny form factor of 15 x 11 x 0.7 mm, as small as a finger nail these cards are fast gaining popularity in the memory card market.
A micro SD card is one-fourth the size of an SD card and is mainly used in mobile phones, portable Audio/Video devices such as MP3 players and PMPs, expandable USB flash memory devices, not common in India yet. There are adaptors available in the market that convert a micro SD card into an SD, mini SD or even Memory Stick Duo cards.
Advantage - Impressively small.
Disadvantange - Slow speeds of data transfer.