Is this an intellectual exercise? Hmmm, how about large when consider by Economic Efficiency (as measured by output / land use)?

GDP / Land mass.

  UK: ~8,780,428 (  2,139,000,000,000 /   243,610 ) [1]
  US: ~1,450,745 ( 14,256,000,000,000 / 9,826,675 ) [2]

Both end up being considered massive in comparison to my "piddly" little country:

        ~111,732 (    851,170,000,000 / 7,617,930 ) [3]

[1] UK 2009 PPP GDP estimate. http://en.wikipedia.org/wiki/United_Kingdom

[2] US 2010 PPP GDP estimate. http://en.wikipedia.org/wiki/United_States

[3] AUS 2009 PPP GDP estimate. http://en.wikipedia.org/wiki/Australia