If you're making a portable you probably need something to watch it on. (Unless you want to guess what's happening in the game, but I wouldn't advise that) Anyway, this forum is your "Hacking a pocket TV/screen" one-stop solution. Share your experiences and knowledge here.
Well you could hook both of them up with their seperate power supplies. If you have the hinge part disconnected you can connect the AC jack to its normal cord, and the AV/MULTI out to the PS2. Oh, and the PS2 to its normal AC jack. Err wait, did you mean connecting as in a portable?
Well Im not sure that the Psone LCD can handle the voltage that the PS2 cord uses. Hang on... just a thought the voltage on the PS2 is like 8.5v right? well I guess you could use that on a Psone screen you would have to get a male plug for the PS2, and a female then just replace the two on the smaller board of the Psone LCD (the one with the pass-through ports for power). I guess that would work, but don't try it yet I'm not sure if it would trip some fuses, and I don't know the polarity of the PS2. Can anyone confirm this for us?