South End's many artist galleries at 450 Harrison Avenue will be open to the public. Parking is plentiful and you can spend a couple of hours looking through some very unique galleries. If you get thirsty after all that walking there are several lounges and restaurants just steps away (sorry those are not free).
On Saturday and Sunday right next to 450 Harrison Avenue on Thayer Street, sixty designers, artists and artisans are attending the 1st Annual Cabin Fever Indie Gift Show. According to the website, cabinfevershow.com, you can choose from all sorts of gift items. The show is put on by the people who run the South End's SoWa Open market. I'm thinking of stopping by - they have asked that everyone pay $2 admission - which is nearly free (esp. when you consider parking is free). If you happen to be unfamiliar with the South End check out their website which provides directions.