There are a few shops downtown, a nice clothes shop, The Grasshopper Shop. They do carry quite a few very expensive items of clothing and shoes, but they also have a nice collection of T-shirts and other ods and ends including some wonderful perfumed oils.
Whether you go out on one of Capt Bill's boat trips, which I highly recommend, or take the boat ride that they offer downtown, which is good, but not as detailed and more expensive that Bill's.
Another nice trip is the boat ride out to Isle Au Haut.
If you can, try and get out in a boat to really appreciate the beauty of this island.
I don't know why, but I never expected to find a beautiful little lily pond like this one on the island. It really is a treat.
The little houses - I don't remember the man's name that made these, but they used to sit on his front yard, They have since been moved downtown.