Exactly: seems easy to find, but no luck so far. I remember I've changed in on Ubuntu, but from the other hand - I don't really remember how.
You'll find it everywhere - LC_COLLATE="...", export LC_COLLATE, yes, but it works only from shell, and only for shell apps. GNOME seems to ignore it.
What's the deal with this collation? Since very old times, Amiga SD floppies - I used "_" and "!" on beginning of directory to make it displayed first. Fast, convenient, life-saver sometimes. But not any more, not in GNOME. There is this STUPID collation which makes "!zed" listed after "zac" which is real PITA for me. Enough - LC_COLLATE="C" and all works as expected. But how? I tried to add it to /etc/init.d before GDM loads, to ~/.rcdm /.bash_profile. No effect. GNOME ignores LC_ variables, I think it overwrites them per user or session from... I don't know where.
BTW, I don't want to change other locale settings, or displayed language. That's what LC_ variables are for. I know Nautilus respect LC_ settings and uses LC_COLLATE for sorting.
Sorting in Nautilus was often reported as bug, which made its developers pissed - well, I don't blame them - why add manual configuration when Nautilus is a part of GNOME and uses its system settings? Anyway, how to change them? I mean permanently, I want my "!" and "_" directories on top! And yes, I've searched the friendly Google. None of the things I've found worked.