fullbright does not work with lighter2 maps so now that most maps are lighter2 it no longer works sorry
wrong.
using the -fullbright option works in in the BD map where without it half the maps is of black textures and is necessary to use that option. It also works in the gugrontid for a fact (i had left the -fullbright option left on in the planeshift shortcut by acccident) though that map is generally well lit. i know a few users that use it.
if windows: make a planeshift shortcut and in the shortcut target field add -fullbright after the "planeshift.exe"
I can't vouch for other maps though so caveats for those. Try it I guess and see what happens. You lose all shadows and it doesn't look nice graphically but playability is far more important obviously.
just clearing up this myth about not being able to use -fullbright.
If you're on a mac I'm not sure how to help you but if you do know how to add -fullbright alot of mac users would appreciate it b/c it seems alot of them are wondering how.
there is another thread about black textures:
http://hydlaa.com/smf/index.php?topic=31713.0 that has a little bit of relevance and talk of another option "-relight"
Good luck and don't be dissuaded from trying planeshift if this works out for you. Fortunately there's community and while someone might not be totally knowledgeable, the community as a whole is.