Memory Stick
The Memory Stick PRO, introduced on January 9, 2003 as a joint effort between Sony and SanDisk, would be the longer-lasting solution to the space problem. Most devices that use the original Memory Sticks support both the original and PRO sticks since both formats have identical form factors. Some readers that were not compatible could be upgraded to Memory Stick PRO support via a firmware update. Memory Stick PROs have a marginally higher transfer speed and a maximum "theoretical" capacity of 32 GB, although GB-sized capacities of more than 2GB are only available in the PRO Duo form factor. "High Speed" Memory Stick PROs are available, and newer devices support this high-speed mode, allowing for faster file transfers. All Memory Stick PROs larger than 1 GB support this high-speed mode, and High Speed Memory Stick PROs are backwards-compatible with devices that don't support the high-speed mode. High-capacity Memory Sticks such as the 4 GB versions are expensive compared to other types of flash memory such as SD cards and CompactFlash. , 512 MB Memory Stick PRO can be bought.