There are PSP roms (or are they considered ISO's) that have been dumped, but you have to somehow load them onto your PSP--and I don't know how to do that.
But the roms/iso's themselves are rather large: between 200-700 MB, rared.
Basically the same size as PSX ISO's.
If you want the roms/isos, try looking on torrents sites, Emule, DC hubs, IRC,and Newsgroups.
