Last night, I went up to Griffith Observatory with some friends, to catch talks by George Takei and Ray Bradbury on the occasion of Yuri's Night. The newly renovated Griffith Observatory is really nice. An underground exhibit hall was dug out of the ground in front of the Observatory and then covered over. There's a scale model of the eight planets in the Solar System, and the Leonard Nimoy Event Horizon Theater. It was all very well setup.
They really play up NASA and JPL, too. The shuttle bus shows a video that mentions JPL sending mentions to every planet in the Solar System. (Which we can say now that Pluto has been demoted) All of the stations devoted to the planets has imagery from JPL, as well as the always popular scales that tell you how much you weigh on Jupiter.