Introduction: NES GBA and PSX Games on Your IPhone or ITouch
Already jailbreaked your apple?
if so then load the Emulators from Installer and run them.
(If not then see my instructables for hacking 1.1.2 and 1.1.1 iPhone/iTouches)
If you can install the emulators then just add the following Sources to installer and ...viola!
The Roms can be installed and run in a few minutes!