Thanks for the compliments.
They are constantly on. There seems to be a constant voltage draw to the speakers regardless of whether or not anything is playing through them. It is probably less than .8v but more than .5v. They are dim though when nothing is playing, like the beginning of the video before the music starts. Since they are wired up through the speakers, inserting headphones into the jack causes the lights to go out since all power to the speakers is re-routed.
I haven't noticed decreased battery life at all; these are relatively low powered LED's with a 3.6v peak. They're powered directly off of the speakers, so they wouldn't require any more power than the PSP normally does.
This wasn't too difficult of a mod, but I have previous soldering/circuit experience as well. I wouldn't make this your first soldering project! The actual contact to solder to on the LED is about the same size as the E on a Liberty dime. Seeing as this mod was *relatively* easy, it makes me wonder what I could do with the rear UMD door given some time, some thin plexiglass, and some more LED's.
As far as legality, I don't see why this would be illegal. I understand why custom firmware is, but Sony doesn't take a loss when I do an LED mod like this. I would like to have it known that I don't support piracy, but I do support homebrew. Third-party developers need incentive to make games. Piracy removes that incentive. Third-party developers run away FAST when piracy becomes too much.
Example of good homebrew that doesn't hurt Sony, but in fact helps people!
http://pspupdates.qj.net/PSP-homebrew-Nanodesktop-Blind-Assistant-CFW0005/pg/49/aid/128605
