John
I highly recommed a flight along Cape Cod, including Provincetown and where the pilgrims landed, if you can arrange it.
Probably best from Plymouth - an easy drive from Boston.
I did it in a fixed-wing so can't recommend helicopter schools.
The Cape is well worth visiting - wonderful scenery (especially the coastline/beaches) - highly recommended.
So is Martha's Vineyard if you've got the time. It's a very interesting island. (If you saw Jaws, you'll recognise 'Amity' and several other key locations.
)
I looked into flying a Bell 47 not far from Boston, but ran out of time.
If you're interested, I could look it up and give you the details.
Tudor
Edit
Just remembered. The Bell 47 was at Ryan Rotors at Plymouth airport.
Expensive by American standards, but not by UK.
If you haven't done it already, it's well worth flying a B47 if you get an opportunity.