Memory Stick (MS) - The Memory Stick is Sony's proprietary development. There are also sub-types such as Duo (MSD), Pro Duo (MSPD), and Micro (M2). However, currently the storage capacities (Maximum 8 GB) and writing speeds are not competitive with other card formats. But if you have opted for a Sony hand held device, then you will have to use a Memory Stick as other cards are not supported.
Advantage of Memory Stick (MS) - Originality is maintained due to its proprietory nature.
Disadvantage of Memory Stick (MS) - Slow read/write speeds, expensive and it can be used only with Sony products.