Infinity 2.0 released for the PSP, allows for persistent CFW on all models of PSPs on 6.60 and 6.61 | GBAtemp.net - The Independent Video Game Community
New CFW for PSP , the ARK-4 ! - YouTube
PlayStation Guide
Sony PSP CFW 6.61 on PSP-1000 and PSP-3000 - YouTube
PSP Custom Firmware 6.00-6.61
Installing Custom Firmware on a PSP : 9 Steps - Instructables