(I started writing this before last 2 posts)
@Yaskina
Hey, I think You misuderstood (not everybody here can clearly express his thoughts in english) and You are overreacting a bit. For example - it wasn't so obvious for me, that You had in mind only reducing number of colours (quote: "...by discarding
all of the colour information in the PNG"). And where are the flames in above posts ?
I too sometimes don't understand, why people waste so many resources (memory, disk space, cpu power) and why don't they optimize things; and sometimes that thoughts are reasonable. But it is simply hard to belive in Your statements, because most beatiful, recent 3d games occupy gigabytes of disk space and they use high resolution graphics with 32-bit colour, (plus normal maps, specular maps etc...) Using
16-colour textures in modern game sounds... ridiculous (no offense, and I do not deny the possibility, that in this particular case You are right, but I would need a proof). You write later about 256
k colors, which sounds much more reasonable.
So I ask for concrete example, maybe a screenshots from PS showing no difference in appearance between original and converted graphics? If You don't know how to modify map, or You have no time for this, just tell, which textures to convert and to what format, and I (or somebody else) can make a comparision. I don't want to experiment with all of textures, so Your experience and intuition is welcome here

. I really would like to try it

.
I think You can use any free, public "virtual disk" to share Your files.
Regards
P.S. Please, please, try not to use agument "I was doing this for xx years, so yes, I am right!". These kinds of statements often meet opposition (conscious or subconscious) and... sometimes are untrue. A bit of diplomacy is always good. "I keep track of trends in computer graphics for xx years, so I am convinced I am right" sounds better 