Amy Winehouse

Substitute for PSP Memory Stick?

My dad just bought me a new PSP system from Kmart, and the package didn’t come with a Memory Stick. I need one though, ’cause I basically can’t enjoy my system without it. I can’t save images from Google image searches, I can’t look at YouTube videos, I can’t save any game data, and I can’t transfer music, picture or video files, among other things. Is there a substitute for a Memory Stick? I’ve tried SanDisk SD cards from my mom’s camera and Fujifilm SD cards, but they were slightly too big to fit. Any other cards that will serve a Sony Memory Stick’s purpose?