Granby Street is spattered with Antique Shoppes. Some are within walking distance..but we generally scooch the car along the way. After a fun day of antiqueing you could go to the Painted Lady for lunch. A large 3 story row house painted crazy purple and pink is known for its cuisine and tea room. They also have a neat shop on the top floor.
If you are looking for something less formal for lunch...Doumar's on Monticello (east one street over) has great bbq and ice cream, or on 330 West 21st Street the Bakers Crust has the best sandwiches you will ever taste on fresh bread!!