There are many more ways that different groups get around the coordination ban. Roll Call
's Nathan Gonzalez
recently wrote a compelling piece
about the way campaign committees like the Democratic Senatorial Campaign Committee or the National Republican Congressional Committee talk-without-talking to their independent expenditure arms, which the law stipulates must remain separate. (The clever use of ostensibly inane websites holding troves of opposition research that anyone can access - or use to make a 30-second TV ad -- is a large part of it.)
When outside groups air ads, remember that while there is no official coordination between the organizations and the campaigns they support, there is still plenty of unofficial nudging, winking, and nodding going on.