I'm a bit new when it comes to modding PSPs, but I'm not completely useless, so listen up!
I had a great idea that I don't think has been done before. A non intrusive 2nd nub using the PSP remote.
Using a program called PSPRemap, I can remap the buttons on the remote to /\ [] O X.
Then I can fix on a razor x between that and a second nub and voila, a second nub through the serial port.
Can anybody think of a reason why this wouldn't work, I'm not 100% sure on how the Razor X works, is the PCB itself actually an A2D converter, or with the nature of the PSP nub do I not need that... if not, then I think I'll order that razor X and PSP nub !
Lame paint illustration:
