We sell SD/MMC Card!
SD and MMC (MultiMediaCard) cards are nearly identical on the outside but technically different on the inside. Not all cameras that use SD can also use MMC cards, check your camera''s user manual. SD cards are generally much faster than MMC cards. 
SD cards were originally designed to hold copyrighted musical content and prevent its unauthorized duplication. Although this use was not widely adopted, SD cards have become the flash memory card of choice for digital cameras because of their small size and low power consumption. 
SD cards range in size from 16MB up to 4GB. As with other flash media, SD cards come in different transfer speed ratings. Most SD cards not marked "High Speed" or "Ultra High Speed" are probably only ~2Mb/s capable. The latest cards are capable of transferring data at 8-10Mb/s such as the ATP 60x, SanDisk Ultra III or Extreme cards. Transfer speed is an important factor if you record high framerate motion video or high quality audio tracks. Many digital camera makers only certify their 30fps VGA motion video capability when using "high speed" SD cards.