Inside the battery cover is the sim card slot, as well as a standard micro SD (Transflash) card slot. The micro SD card is not hot-swappable as both the rear cover, and the battery must be removed to access it. I have only tested a 1 Gig card, but cards up to at least 4 Gig should work fine. I did initially have difficulty getting the S282 to recognize the Micro SD card. After a few tries, it suddenly started seeing the card, and allowed me to format it.