you should use a piece of diffuser plastic behind it.... I'd like to do the same and have spent some time thinking about it.... I'm not sure where to get it... but I bet you can find it on google....
I've also thought about using EL board (indeglo watch light). There are 2 reasons not too.... require a high freq oscillator (which may cause interferance with PS2 processor) and the crap is not cheap. I have found that Wal-Mart carries little nightlights with a 2 inch circle on EL board in it..... and it's about $5.... haven't checked to see it one would fit... and they run descently off of 120v 60Hz.... so the incoming power could be used to power them.... but a higher oscillation allows for a brighter light.
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