I've added the zip file of all the Facebook Online icons that replace the usual green circle when you go online using Jabber/Facebook.

The structure of the zip file shows exactly where they go.

usr/share/icons/hicolor/16x16/hildon/general_jabber.png
usr/share/icons/hicolor/24x24/hildon/general_jabber.png
usr/share/icons/hicolor/32x32/hildon/general_jabber.png
usr/share/icons/hicolor/48x48/hildon/general_jabber.png
usr/share/icons/hicolor/64x64/hildon/general_jabber.png

They need to either be copied over (and replace the originals) using xterminal, midnight commander or using SSH from a pc/mac with a program like WinSCP.

RootSH is needed if your doing it all from xterminal or midnight commander though.

I don't know if RootSH is needed using SSH over pc/mac (or WinSCP).

The 2g/3g icons are in one (or more?) of the folders in "usr/share/icons/hicolor/" somewhere, but i don't have time at the moment to upload those.
Anyway, i found the 2g/3g icons somewhere in these forums, possible the 95 page long "MODS" thread.