Recently ordered an 8GB Sony memory stick online (3rd party Amazon seller, 23$ including shipping), and it had some trouble with data transferring. I tried reformatting on the computer and I noticed the maximum size for it was only 3.5 GB, but when reformatting on the PSP it goes back to 7600 or so MB. Funky stuff, so I checked the Magicgate and it says Supported. Not sure what's going on.

On the back it says

(giant CE symbol)
MS-MT8G
J812L1L
AUBE10SS000
Made in Korea