If you have an evening free in San Diego, I highly recommend visiting one of the local drive-in movies. Doing double duty as a flea market on weekdays, this run down parking lot may look like nothing special, but I disagree. Just put the kids in pajamas and drive out to the South Bay Drive in and see for yourself. Their eyes will light up when you bundle them into the back of the car with blankets and pillows, turn up the radio and watch a movie. You can bring your own snacks and drinks or buy from the reasonably priced snack bar there. With three screens showing different first-run films, there are options to choose from. While we were there, they played Area 51 (G), Twilight Saga New Moon (PG-13), and The Blind Side (PG-13), only a week after their opening day, though I am assured that they open at the drive in on the same day as other venues in the same area.
Something to keep in mind when taking children is to check that the other movies playing do not contain nudity or objectionable visuals as all three screen are viewable from the lot, though you only hear the audio that your radio is tuned to receive. You may wish to being a small battery operated radio to hear the audio instead of running the car for two straight hours, just to be a little more green without worry over the car battery dying. You can also bring lawn chairs if you prefer to sit in them instead, but the really fun part, for the kids at least, is watching a movie from the car. We simply pulled in facing away from the screen, opened the back of the SUV and let the kids snuggle up in the back with a nest of pillows and blankets. They had a great time, and you will too.