Just spotted this little gem, it turns out that when you hold down the international keyboard button, you're given a "popover" style menu which allows you to drag to select the keyboard you wish to use.
Very helpful! In fact yesterday I was wishing apple had something like this, turns out they do and I just hadn't noticed it!
I wish, though, that it made you select int'l keyboards like using the popover (instead of allowing you to quickly toggle keyboards by hitting the int'l key). Too often I find that I've accidentally hit the int'l key and swapped the keyboard to a different language! :P