#4 I like the most, but I don't want a black background and probably some colour should be nice #5 and #6 nice to use as a starting point to design more entries.... but not yet what we are looking for
for all: It should express more about 'communication', 'mediation', 'advertisement'
about #9 You've now made the innercircle of the wheel like some sort of 'speech bubble', can you find another way to express 'communication'? I would like the wheel to be just a wheel ...