The Maryland Science Center is always a great place to spend some time, but on Saturday at 3pm, you can go and participate in "Earth Hour," when all the computers will be shut down and there will be activities teaching how to conserve energy.
Last weekend the Maryland Zoo celebrated Samson the elephant's third birthday, and this Saturday at 1:45 p.m., they'll mark Zoe the giraffe's (pictured) 16th year with a special demonstration and chat with her keeper.
On Saturday at 2p.m., the Enoch Pratt Free Library's central branch is hosting a free screening of Despicable Me as part of its family flicks series.
When I was a kid, earning a spot on Nickelodeon's kid game show Double Dare was the coveted kid dream, like maybe being on American Bandstand was once. On Sunday, you can take your kids and live the dream at the Owings Mills JCC's Family Double Dare, for ages 6 and up. Get slimed...
And of course, there are the perrenially great-for-kids activities, including the Walters, which, besides the great, often kid-friendly exhibits, has a fantastic play area on the lower level with lots of dress up stuff, puppets, puzzles, and an art room where there are facilitators to help you and are kids make great projects and bonus: FREE; The Baltimore Museum of Art frequently has great kids' activities; Also, the Marlyland Science Center ($3 off admission before noon on Saturdays, plus the weekly egg-drop contest), Port Discovery Children's Museum, The Zoo, two Storyville locations (we LOVE Storyville), The American Visionary Art Museum (also with kid-friendly exhibits, and the treehouse/sculpture out back if it's not too cold), the various nature centers and conservancies (Oregon Ridge, Irvine, Howard County), and—of course!— the Aquarium.