A Wind Farm Offshore
A proposed wind farm could provide half of the electricity needed by Cape Cod, Martha's Vinyard, and Nantucket. This NY Times article (you can use "songdog.net" as username and password) describes the idea.
Opponents raise a number of valid concerns, but I say: you may think it's ugly, but do you really think it's as ugly as a coal plant? You may think it's dangerous, but do you really think it's as dangerous as a nuclear plant? You may think it's bad for the environment, but ... you get the idea.
And please, please -- does anybody have a better idea?