It is a Gnome Panel widget... I myself use USA and Russian Phonetic. Just create a Keyboard Indicator widget, right click, add whatever keyset, you want, and then change the key. I know for a fact that you can use Alt and Shift (although on one of my computers, it is a little faulty and refuses to aknowledge the left Shift and Alt. I usually use Scroll Lock, myself.
-- Leonid
