spoke with the people at siraco knife sharpening service in somerville. they are in the process of arranging drop off and pick up locations -- the first is "the fabric corner" in arlington (mass ave at mill street between arlington center and arlington heights).
he also mentioned a placed in everett, and he said they're working on a harvard square location. the phone # will remain the same, so call for updates. 617.628.6071.