Via Tyler Cowen, an interesting comment over at Mark Thoma's place once again demonstrates how much room Americans have to stretch out:
Princeton University is located in Mercer county which has a population of 350,761 (2000) and a land area of 229 square miles. This works out to be 1,532 people per square mile. This is somewhat above the average for all of New Jersey of 1,174 people per square mile. Note that New Jersey is the most densely populated state in the nation.
By contrast, Seoul (10.356 million people) has a population density of 44,310 people per square mile. Central Paris (2.154 million people) has a density 64,186 people per square mile. A better comparison is Urban Paris with a population of 9.645 million and 9,173 people per square mile. Greater London has 7.7 million people and 12,644 people per square mile.
