actually...
Firmware 3.50 cracked - PSPGN - Sony PSP news, games, downloads, hacks, & more!
I know nothing about PSPs, but a quick google search turned up that 3.50 can be cracked ;p
Oh.. that doesn't neccesarily mean it's down-gradeable..
I'd liek a PSP sometime, so I can play PSX games on the move...