I have seen plans for overclocking a PSOne... and adding more ram to the Xbox... but nothing so far on the PS2 in these areas.... Hell if you went crazy and water cooled the chips (RAM, GS, EE) I don't see why you couldn't double the clock speed... Just finding what to change......only thing I think I would worry about in an OCed Ps2 would be the chips design limit... what it could take... the safest way of OCing the system would be do it in small increments untill it started to show instability....then back off a little...
Instabilities in the EE, GS or the RAM could mean that you've met the limit of the hardware... BUT HEED THIS WARNING: Doing this could result in the death of millions (transitors that is) which , by the way, is bad...mmmkay.
PS3 Slim 320GB
PS2 v11 exploit w/300GB Maxtor
PS2 v10 exploit w/80GB Samsung - Network Games
PS2 v10 exploit w/60GB Samsung - Network Games
PSP 1001 3.52M33 w/10GB total storage
NDS DSReal 4GB