Do the surface mount flash storage chips work work like MMC cards? I see a bunch on digikey that interface over SPI but I don't know if they are identical to MMC cards so they can use the same library. Does anybody have any more information on this?
What makes you think it has anything to do with a MMC card interface ? 25xx chips are SPI Memory chips, and cannot be used with the MMC library. If you counted the number of pins on the chip you would have noticed there isn't enough for a MMC-interface 
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