The Economist created a map of the United States that matches each state with a national economy of comparable size as measured by Gross Domestic Product in 2009. It's interactive. So at the link, you can hover your cursor over each state and get more detailed information.
Link via Ace of Spades HQ
Previously: Map of US States Showing Equal Population
Really really interesting map. Thanks for the link and posting!
http://en.wikipedia.org/wiki/Comparison_between_U.S._states_and_countries_nominal_GDP
Your right, it's way off. Looks like the GDP of MA is around $365 billion for 2009 and the CIA Fact Book puts it at about $600 billion for 2009.