Not to take anything away from the Be Seen commandment, but my general philosophy is to ride like I'm invisible.

This comes from several conversations with over-the-road truckers who ALSO complain mightily that car drivers don't see them. If <your stereotypical driver here> doesn't see an 18-wheeler, s/he most certainly won't see a person on a bicycle, no matter what I wear. (It probably can/should go without saying that the trucker is in a much better position if a car driver does something stupid, still, they are protective of their driving record.)

So, by all means, wear bright colors, but don't assume anyone sees you.