I have lived in Boston for about 5 years, and my mother and stepfather are coming to visit me next week. I have plenty of places to take them to eat, but I am not sure what to do with them during the day! In previous visits they have already done all of the touristy stuff...Duck Tours, Faneuil Hall, Back Bay, MOS, etc..I was thinking about taking them to Cambridge, perhaps? Any thoughts from Boston locals or people who have visited and had great times doing things other than the standards?

I love Boston.