I really want to get Final Fantay 7 off the psn store, but I only have a cash card not a credit/debit card. My mum has said I can use her card but I dont want to becuase I know if i use it once it wont stop there lol .My mate has just downloaded it to his Ps3, and I know they can be re-downloaded a number of times I'm just no sure how many, Is it possible for me to take my PSP to his house and copy the FF7 game file to my PSP and then take my PSP home and upload final fantasy 7 onto my ps3?

You can get his FF7 onto your PS3 for free without using a PSP.

how do i do that? and thanks for replying

use his account on your ps3 and download the game.

That's pretty much all you can do. If you live in the US you can get  PSN card though.

You cant copy the game to the PSP, because your PSP needs to be registered on his PSN account, and that would destroy every game u have on your psp downloaded from your account, and vice versa.