After several years of waiting, I finally got to go to the remodeled Griffith observatory, which was lots of fun. Although I failed to get tickets to the planetarium, I was still well occupied for a couple of hours.  Here are my general impressions/comments:

• Buy/print reservation tickets online, park early at the Hollywood & Highland complex and take the shuttle up
• Rush to the giant refracting telescope first (entrance on side of building) because there will be a wait, and it's getting colder by the day. It's a quick look, but the man there is very knowledgeable and will answer any and all questions, especially those posed by the small fry.
• The Tesla electric current things is a blast. Try to drift around so you can hear one of the Guides give his speech about how Thomas Edison was the better showman. The scientists' rivalry was also addressed in "The Prestige."
• Missed the camera obscura. Darn.
• Definitely catch the cheesy but highly informative 18-minute film at the Leonard Nimoy Event Horizon Theater (showtimes posted). It shows just how much was done to the observatory, including raising the entire structure to build the underground area.
• The Depths of Space - Pass the lovely wall comet made of costume jewelry (in heavenly body forms themselves) and then down to the lower level, where you're in the Milky Way Galaxy. Weigh yourself on the different planets (the former Pluto is particularly gratifying) and take your picture with Einstein.
• There's actually so much more that I didn't mention here. Just go already.