Rockport, MA is great, too (motif #1). Downtown Boston is fairly walkable depending on the weather. Rowes Wharf has some interesting architecture and plenty of street shooting. The aquarium is worth seeing, photography or not. I've never been to the arburetum (sp?), but it might be worth checking out if you like plants.
Almost anywhere on the Cape is picturesque, imo. This time of year, the tourists haven't really hit, yet, so you can still drive somewhere without it taking 3 hours to go 2 miles. I like Woods Hole and Falmouth as well as Provincetown - totally different areas. The National Seashore is great.
If you have time to take the ferry to Nantucket or the Vineyard, go for it. Both are very scenic. I honestly can't remember now which one has them, but there is a group of cabin-like houses in cool colors (think it's on the Vineyard) - they were originally part of a church retreat, I think.

I miss Boston. Wicked bad, in fact.