My favorite exhibit is probably the one dedicated to mathematics, but close behind are the electricity presentation (and playing with eddy currents), the butterfly garden, the cotton-tailed monkeys, and all the fun interactive stations on the lower level. Currently, they have a special exhibit on baseball with all sorts of neat historical artifacts and information...and Curt Schilling's bloody sock from the 2004 World Series. Not nearly as cool or as historic as the bloody garment Gandhi was wearing when he was assassinated that I saw in India, but neat nonetheless.
I am going to love being this close to Boston. We'll be a train-ride away on the commuter rail, and for some of the other attractions, driving into the city won't be too difficult (New Jersey driving has made me rather fearless). There are all sorts of things I would love to do: the Aquarium, Museum of Art, the Children's Museum, catch a few shows, etc... I hope that we get to go into Boston at least once a month.
In the spirit of the science-y day I had, I leave you with a webcomic from xkcd:
