Greetings from Boston, an exhibition of vintage postcards currently on display in the Johnson Lobby, allows visitors to tour "vintage" Boston through postcards depicting some of the city's most famous places and spaces in bygone days.
Where: Central Library Copley Square, Johnson Lobby
When: Now through March 31, 2011
Monday-Thursday: 9-9
Friday and Saturday: 9-5
Price: I believe it's a freebie!

