I say either wheel bearing!!! mine went bad on the drivers side and it was a vibration that we heard on the passangers side.... on my truck it would make a really nice grinding like noise when the wheel bearing went out on it (they went out often, Had a snow plow on the front).... also just one other thing to check... take wheel off and see if there isn't any debri stuck in one of your brake pads.... with my truck I would often get rocks and other debri stuck in the pads and that would make a nasty noise too, most the time that stuff would come out on its own... but, not always.
