I am sure that many readers dislike Krugman for his relentless - and often deceptive and hysterical -political partisanship in the NYT. However, he has apparently made some genuine contributions to economics.
The NJ's link to Marginal Revolution on Krugman's Nobel led me to this somewhat technical essay by Krugman on The Role of Geography in Development. Quite fascinating, whether you agree with his assumptions or not.