If you are a Bank of America card holder, be sure to check out their Museums On Us program. Each month during the first full weekend of the month (so for March, that would be this weekend), you can snag free museum admission at more than 100 museums. You can search for the nearest participating museum on their site by searching by state.
For instance, in my neck of the woods, a BOA card holder could enjoy the Phillips Collection in D.C., which houses art greats such as Picasso, Renoir and O'Keefe. Or, if you wanted to take the kids to Richmond, you could visit the Children's Museum there.
Check the list for museums near you. Save some bucks by planning a trip to the museum for the weekend that will be free.