If the weather is nice, consider going to Salem and/or to some coastal towns, such as Gloucester and Rockport or Marblehead (within an hour's drive). I think they are all reachable by commuter rail from North Station.

The MIT campus is not beautiful, though the new Stata Center, a Frank Gehry building, which is rather interesting architecturally, should be completed by then. Harvard Square area, on the other hand, can be very pleasant, especially with street performers and such.