I think both America and Britain stereotypes of each other are completely pointless.
Most Britons think all American's are fat, greedy (food and money), stupid and every American thinks they rule the world, and I'm guessing most Americans think that we speak very posh, drink tea, are are extremly arrogant.
I do find it quite funny though that America's greatest friend (the TV) was invented in my home town (Hastings) and many Americans seem to think that the TV was their invention.