I was on vacation and chillin' in the car and iwas just mulling over some ideas i had and wanted to run one by you.
People have said that the PSP cannot be a host for USB so you cannot use it to connect to a flashdrive or the like. BUT, you can have a computer or other host intermediate between the two.
So i thought, why not create a small "USB host" device? just a few IC's and a battery, with a female plug to accept the flashdrive, and a male to go to the PSP. It would just run some code that makes the two continuously communicate, or share files.
I do not know the first thing about programming or electronics, other than current/voltage that you learn in physics class. The PSP would probably have to be in USB mode for this to work, so it's probably not gonna work, but hey. Just an idea i had never seen before, just getting it out. Speculation. Cheers!