According to the US State Department website, the UK only requires a valid passport (no 6-month minimum reqt, etc):

"While some countries impose a minimum passport validity of three, six, or nine months for arriving passengers, there is no such requirement for the United Kingdom. U.S. citizens seeking entry as tourists or visitors are simply required to present a valid passport, as explained on the website of the UK Border Agency."


US State Dept website for "International Travel" (just pick your country!):

- http://travel.state.gov/travel/travel_1744.html

Here's the one for Great Britain (UK):

- http://travel.state.gov/travel/cis_p.../cis_1052.html