The Maryland Science Center was a fun and educational place to spend our last afternoon in Baltimore. We spent most of our time in the Newton's Alley and Your Body exhibits. The other exhibits mainly focused on dinosaurs and space, and they simply weren't as enjoyable.
The first floor of the Center features working geyser models and--for an additional fee--a Segway tour. Newton's alley has a lot of classic hands-on physics exhibits. I didn't learn much of anything new in this area, but it was fun to play around and apply or demonstrate simple principles. The Your Body exhibit was more interesting, offered more learning opportunities, and had more unique exhibits. The best exhibit featured an interactive lie detector, so make sure to bring a friend. The instructions ask that your try to guess a number that your partner is chosen, but it's also fun to ask embarrassing or nagging questions for which you've been dying to know the truth.
It was a fun, although half the exhibition areas were kind of boring. But that allowed us to spend more time in the areas we enjoyed instead of rushing to see everything. I recommend it.