The size of available removable memory cards has continued to grow since they were invented. The latest format for smartphones and tablets is microSDXC bringing 64GB of capacity.
This format is replacing the original microSD (with storage up to 2 GB) and microSDHC (SD High-Capacity, with storage up to 32 GB). The format supports up to 2 TB of storage.
Cards of that size are still years away. Kingston is just now introducing a 64GB one. Rival SanDisk came out with its first microSDXC memory card over a year ago, but has yet to release anything with more capacity in this format.
As a cutting-edge product, the price isn't low -- Kingston's version of this card has a suggested price of $100. SanDisk's goes for $50 - $60 in stores. But now that there are two companies making these cards, competition is likely to push down prices.
Some Android smartphones and tablets support microSDXC cards, although not all the these say so explicitly. Some say they support microSD cards up to 64GB in size, which is the same as saying they support microSDXC. The device must support the exFat system.