If the micro SD is not formatted and is bigger than 16 GB you have to format on a computer, android 2.1 limit. The Captivate will work with a 32 GB micro SD card, I have a net usable 29.29 GB on external SD on my phone. I am pretty sure Class 2 is about all that is available for 32 GB micro SD card (I could be wrong). Class rating have to do with how fast a card can read and write. If I was shooting HD video I would go to a class 6 probably (do not know if this is needed or not). Most comments I have read say a class 2 is okay for a cell phone.
there is a 32gb class 6. Around $200. Im sure its awesome if you have a money tree. I got a 16gb class 4 for around $44. Playing some 700mb avi episodes of Dexter at 960x544 i downloaded off the web a few year back i have no lag in video or sound.
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