take with a grain of salt.
from what I can tell the facebook button is some kind of iframe element with an inline styling width of 300, you need to set the width of that element to about 80px, then it will fall into place to the right of the google plus button (which i guess isn’t exactly what you asked for, is it?) so if you could put that element before the google plus one in the html flow and then set it’s width to 80 instead of 300, that should do it. hope this gives you some ideas if nothing else.