I just got back from my first trip to Boston and I absolutely loved it. Since the time in the city was a quick day trip (before heading to Marblehead to see a dear friend), I didn't do any public trans and put a real wear on my Birkenstocks. I was ready to consume as much public art as I could in a few hours. I'll have to hit up the ICA the next time I'm there and have an entire day to commit.
Tourist note: One of the things I was really set on seeing was the Janet Echelman installation As If It Were Already Here. I asked a couple people where the "Janet Echelman was" and they gave me the weirdest look before going, "Oh yeah, the big net thing-y is this way..." So just use the word "thing-y" and you'll be fine.
I heard the time to see this is at night. It's pretty spectacular all the same.