Well I know I'm gonna regret asking this question, seeing as how people who were smart enough at the time not to upgrade their firmware think they are high and mighty, but I'll ask anyways.
I wanted to mod my brothers PSP, and I saw that he upgraded to the 3.95 OFW. I want to get a custom firmware, but frankly I'm just too damned poor to afford an extra battery and memory card, so I want to know can you upgrade 3.95 OFW to 4.01 M33? If not, are there any alternatives to pandora's battery for someone who has bills to pay and can't spend money on a 40 dollar memory card and battery?