Infinity 2.0 released for the PSP, allows for persistent CFW on all models of PSPs on 6.60 and 6.61 | Page 2 | GBAtemp.net - The Independent Video Game Community
Release: Infinity 2.0 – Enables Permanent 6.6x Custom Firmware for all PSPs! - Wololo.net
Got my PSP GO Today :) it has custom firmware 6.61 : r/PSP