I was thinking about that too yesterday - if EVERYTHING was expanding at the same rate, would we even notice? would it have any measurable effect? For this to even work various universal laws/constants would probably have to auto adjust to give consistant results as the universe grows - ants (after a few billion years of expansion) collapsing under their own gravity to form stars/black holes would be amusing perhaps, but only briefly.

The balloon (ballon/baloon) metaphor still holds up if you assume a molecule sized dot painted on a single molecule of balloon(etc) surface - molecules get further apart when the ballo(ohforgetit) expands, without increasing in size (probably - I've never examined a balloothingy expanding under a microscope).