Heat rises.
FWIW, here's what I do. Open up every window and french door, and crack the garage door open first thing in the morning and leave it that way until the marine layer burns off or the inside temp goes above 72 degrees. Then I close all of those, draw the blinds (so that the inside slats head upward) and live like a mole until about 6 pm (and who cares since I'm at work during that time anyway). When I get home, I repeat the opening, along with using a <a href="http://www.amazon.com/s/ref=nb_ss_gw/102-6487505-3276161?initialSearch=1&url=search-alias%3Daps&field-keywords=vornado&Go.x=0&Go.y=0&Go=Go">Vornado</a> in the master bedroom with the fan facing in (to pull the cool air in). It helps, but it's not perfect as all that great extra insulation the newer Building Code requires is really good at keeping the heat in. We still run the AC all night - and it does run.
Also, if you're not particular about your lighting, replace your standard lightbulbs with compact fluorescents, as they emit less heat (and use less electricity).