Not far from Stonington is New London & Mystic. Have you done the Long Island lights? Could take the ferry from Block Island (if you had the car with you - and if it runs this part of the year). Or, you could take the ferry over from New London. You can do a good chunk of LI lights in a day if you want to. They are well worth the visit, and could be on the way for you.

From Point Judith, it isn't that far to Beavertail. Plus there are a number of lights in the Newport area if you have not visited them.

Dave