PSP Custom Firmware 6.20 LME-1.9 can now be permanently installed! - Wololo.net
Infinity 2.0 released for the PSP, allows for persistent CFW on all models of PSPs on 6.60 and 6.61 | Page 3 | GBAtemp.net - The Independent Video Game Community
PSP Custom Firmware 6.00-6.61
Installing Custom Firmware on a PSP : 9 Steps - Instructables