What's better than a new firmware? A new custom firmware! Yessir... Coming for your PSP, regardless of model, is neur0n's 6.60 ME v1.5. Now you should be using LCFW if your PSP is newer than a PSP-1000 or PSP-2000 (non-TA088v3); and if you're still sportin' an early PSP, drop the "L" and use the straight up CFW.
What's new? The same for each:
•Added a 199/99 CPU clock.
•Fixed a bug in VshMenu when save config.
•Optimizing the patch.
By the way it's recommended, if you're using CFW 6.60 ME -- the non-light version -- that you have a Pandora battery on standby ... you know, just in case something goes wrong when writing to flash memory. Rest assure though, I've yet to read a brick report. LCFW is 100% safe and patches memory on-the-fly (no writing to flash).