Yesterday I took Ryan to the Natural History Museum during our lunch break (it's a short walk from the hotel). It's another place that our OMSI membership gets us into for free, so we didn't feel bad spending such a short time. We went to lunch first, then headed straight for the dinos, T Rex specifically!
We walked through the whole museum, which is set up to take the visitor through time from the earliest beginnings of the planet to the current day. We only stopped when something really caught our eyes, but sometimes that's enough.
The Mars rover exhibit was one we spent some time at. It has a working camera on it that you can manipulate to look all around the exhibit.