The entire weekend is fair game for me but lets plan on Saturday, June 7th for those interested.
Museums to consider:
New England Aquarium: Pretty rad aquarium. Person I know is actually interning there right now.
Museum of Science: They do a great electricity demo and have a lot of cool exhibits.
Harvard Museum of Natural History: Really just walking around Cambridge as a whole is a good time.
Freedom Trail: Super touristy and all that but takes you through a lot places.
Museum of Fine Arts: Another great museum.
Other things to consider:
Sam Adams Tour: It's about a 20 minute tour followed by 20 minutes of drinking with more bars nearby.
Harpoon Tour: I've never done this tour because you have to get there early to get in, it seems.
GrandTen Distillery Tour: Also never done this but I've heard it's good.
Taza Chocolate Tour: I didn't even know this was a place with tours until this past weekend.
Bars to consider:
I'm partial to the Museum of Science and Aquarium, if anybody knows other things definitely bring them up here!