it is a custom firmware and hombrew apps, i also was using it as a mini guitar amp/effects processor at one time so it will already accept a mic (through the socom mic input) i just need to mod the firmware to mulitask so i can run the voice and sound effects apps at the same time. all the software to do this is free as well, and i can play "all" the games too;) as of yet, there is no hardware modifications to the psp is all just software.
you can go to-----------to get everything to do this. it is really simple but be warned, do your homework before trying this....
i am thinking of mounting it on the side of my bfg