Normally we'd rather choke on a well-buttered crumpet than become more American, but now we've got our hands on an iPad, our craving for apps and other goodies means we're suddenly more than happy to become a Yankee poodle.
Because the iPad isn't available in the UK until May, you can't buy iPad apps or books from the UK iTunes store. You could just put UK iPhone apps on to the iPad by connecting it to iTunes on your computer with a USB cable, and they'll work -- but they're made for a smaller screen, so they don't look as good on your iPad.
But never fear, because you don't have to put on ten stone and talk louder to impersonate an American. We've got all the tips to set up a Yankee ID, all for free, without a US credit card.
Be aware that using the US iTunes store outside "the United States, its territories, and possessions" breaks the store's terms and conditions, and you'll have to take responsibility for that when your heart is weighed against a feather.
Update: Thanks to the commenters who pointed out that some iPad apps are available on the UK iTunes store on your PC, which you can side-load onto the iPad over USB. They're a bit harder to find, because there's no dedicated iPad area of the UK iTunes store, so try searching for what you want. You'll still need a US account to get the full selection on your PC, or download apps directly onto the iPad.