I am a Project Manager\Developer for QuArK (Quake Army Knife).
http://quark.sourceforge.net/
Our forum is at
http://quark.sourceforge.net/forums/
QuArK is a map and model editor for various games including Quake 3. I just finished updating two add-on files that will let plp map for Smokin-guns and they can make or edit md3 model files as well.
They can download these addons from here:
http://quark.cvs.sourceforge.net/viewvc ... s/Quake_3/
They will want to get the Q3_SG_textures.qrk and Q3_SG.qrk files. Inside the Q3_SG.qrk file at the top are instructions on how to use them in QuArK.
EDIT by ReD: This post is now a STICKY. Thank you!