Just watch this video, it's very easy, and you won't have to go through all the trouble of buying a magic memory stick and a pandora battery!
(this is how I did it, but you may need a LOT of patience, it took me hours)
[You must be registered and logged in to see this link.]I say "you MAY need a lot of patience," because you never know when your screen will appear like his after he loaded the pictures. This guy was lucky. He got it on his first try -.-. It took me around 150 tries xD. But I've seen people saying that it took them almost a week to get it to work, and I'm surprised that they didnt give up after the first day of trying 0.o.
Anyway, with this, you can download homebrew apps for your PSP like emulators, custom themes, and much more!
Have fun with your hacked PSP!!