I can confirm that it works now, sorry, my bad.
Last time I tried it must have been Gutsy RC instead of final, that's the only explanation I can think of why it didn't work for me before.
I did:
sudo nautilus double click on a .tar.gz (a gtk theme to be exact) drag into a folder only root can write to (/usr/share/themes)
Works no problem now.
I can confirm that it works now, sorry, my bad.
Last time I tried it must have been Gutsy RC instead of final, that's the only explanation I can think of why it didn't work for me before.
I did:
sudo nautilus
double click on a .tar.gz (a gtk theme to be exact)
drag into a folder only root can write to (/usr/share/themes)
Works no problem now.