On Saturday evening, the BBC ran an experiment to to find out the nation's IQ. They basically ran a national IQ test on prime time TV. I didn't see the TV program (hey, I have better things to do on a Saturday night) but luckily the test is also available online.
I tried it this morning and scored 137 which is, I guess, pretty good. Would have been nice to get 140
An interesting result is the map of results by region. The pale colours indicate that most regions were pretty much near average, but notice the higher over average scores for Surrey and Hampshire and the large area of under-achievers in Western Scotland.